UA100960C2 - Installation for neutralization of solid household wastes - Google Patents

Abstract

The invention relates to devices for neutralization of solid household wastes through high-temperature processing and can be used in the system of municipal economy. An installation for neutralization of solid household wastes includes reactor and floor section installed with gap, coaxial with the reactor circular afterburning chamber installed with formation of gap between that one and the floor section, and has a wall common with the reactor and a circular heat exchanger that has a wall common with the afterburning chamber, and crucible and thuyeres installed in the floor section, those with one end are connected to the heat exchanger. Novelty is in that the afterburning chamber and the heat exchanger are equipped with heat conducting plates installed in parallel one with respect to another at angle to horizon not larger than 45°, afterburning chamber is additionally equipped with a ring that closes the gap between the chamber and the floor section, and the thuyeres with the other end are connected directly to the crucible. The installation of heat exchange plates substantially increases time and area of heat transfer from high-temperature afterburning products to wastes and air. The ring in the afterburning chamber acts as a thermal compensator at thermal expansion of the wall between the afterburning chamber and the heat exchanger and forms a directed flow of heated air to afterburning chamber. Supply of heated air by thuyeres directly to the crucible provides complete uniform burning by the whole cross section of the crucible. Such realization of the installation for neutralization of solid organic wastes makes it possible to carry out afterburning at increased temperatures with increased rate of gas mixing.

Description

The invention belongs to devices for disposal of solid household waste by means of high-temperature treatment and can be used in the system of housing and communal services.

A known device for the disposal and destruction of solid waste, mainly medical, which includes a gasification chamber with holes for the adjustable supply of an oxygen-containing gasifying agent and holes for the removal of gaseous products into the heating chamber and an afterburning chamber with holes for the introduction of secondary air. The gasification chamber is partially immersed in the afterburner chamber, with its part where the gasification zone is located. The afterburning chamber is equipped with a heat exchanger. To initiate the process, the installation is equipped with an additional heating source (for example, an electric heater). When processing waste containing harmful impurities, such as chlorine and sulfur, flue gases and/or gaseous products discharged from the gasification zone can be additionally cleaned of harmful gaseous impurities by known methods, for example by passing them through a layer of crushed limestone or other material , which absorbs or neutralizes these harmful impurities. In order to reduce the number of harmful emissions associated with the start-up and shutdown periods of the gasifier furnace, it can be equipped with devices that ensure during its operation portioned or continuous loading of waste into the gasification chamber and removal of ash and other non-combustible materials from it. To ensure the required level of traction, the installation contains a device for creating traction, for example, a smoke extractor or an ejector (patent on the invention

You 2089786, IPC G23S25/00, publ. 10.09.1997).

The disadvantages of such a device are that air for afterburning is supplied locally, which leads to an extremely uneven thermal field in the afterburning chamber and an increase in thermal stresses, warping of the gasification chamber and the body of the afterburning chamber as a whole.

Such a thermal field gives an uneven thermal load on the gasification chamber and leads to an inhomogeneous gasification process. The location of additional heating devices to initiate the process in the afterburning chamber leads to the melting of the mineral residue and slagging of the heating devices. In addition, the execution of heat exchangers in the form of pipes gives a small area of heat exchange and requires the creation of increased pressure (for example, using high-pressure fans or a system from a fan or compressor), so that due to such

A sufficient amount of air has passed through the heat exchanger.

The closest analogue is a mine-type installation for the disposal of solid organic waste with internal afterburning, which contains a cylindrical reactor and a bottom part installed with a gap, an annular afterburning chamber coaxial with the reactor, installed with the formation of a gap between it and the bottom part and having a common wall with a reactor and an annular heat exchanger, which has a common wall with the afterburner chamber. In the lower part, the heat exchanger is equipped with tuyeres, which supply heated air into a vertical channel for the exit of liquid mineral residue. In the upper part of the reactor, the installation contains a collector for the output of combustion products and a device for the forced supply of waste. In the afterburning chamber, gaseous pyrolysis products, coke residue combustion products, and air from the external heat exchanger are afterburned, the released thermal energy heats the reactor wall on one side, and the air in the heat exchanger through a common wall on the other. At the same time, the gaseous products of pyrolysis enter the afterburner through the gap between the reactor wall and the bottom part, and air from the heat exchanger enters through the holes for the supply of heated air (declaration patent for a utility model OA 24044, IPC G23С25/00, publ. 11.06.2007. Bull. Mo 8).

The disadvantage of the closest analogue is that in the afterburning chamber, a low temperature is reached and a low speed of gas passage. During the passage of pyrolysis gas and combustion products through the gap between the reactor and the bottom part, transverse flows are created, a kind of air cut-off, which leads to the prevention of the penetration of heated air through the holes and, as a result, a traffic jam is created and the movement of gases is strongly inhibited, while part of the pyrolysis gas rises along reactor up and goes into the environment. This leads to uneven temperature and homogeneity of the afterburning process in the volume of the chamber. With this execution of the supply of gases for afterburning, the air in the heat exchanger is heated to a maximum of 400 "C. In addition, the supply of heated air for afterburning through the nozzles into the vertical channel for the exit of the liquid mineral residue leads to ensuring the combustion process of the coke residue only in the air supply zone (in the zone "burning apples") and to the freezing of the slag residue on the lances, since the temperature difference reaches 400-500 C, while in order to ensure the supply of the required amount of air, a large number of lances are needed, which do not fit in one row around the channel. In addition, 60 the horizontal arrangement of the pipeline for the output of afterburning products leads to an increase in the resistance to the movement of gases, therefore, with a large number of combustion products, there is a risk of a traffic jam. Another significant disadvantage of such an installation is the high degree of contamination of the output gases with dioxins and furans, since there is no provision for their purification at the outlet, and loading waste from the top of the installation completely excludes the possibility the possibility of visual control and carrying out preventive measures without stopping work.

The invention is based on the task of creating such an installation for waste disposal, in which, due to structural changes in the afterburning chamber and due to the supply of heated air directly into the furnace, it is possible to increase the afterburning temperature by supplying high-temperature products of combustion of coke residue and air while simultaneously ensuring an increase speed of gas mixing.

The task is solved by the fact that the proposed installation for disposal of solid household waste, which contains a reactor and a bottom part installed with a gap, is coaxial with the reactor, an annular afterburning chamber is installed with the formation of a gap between it and the bottom part and has a common wall with the reactor and ring heat exchanger, which has a common wall with the afterburning chamber, and also installed in the bottom part of the furnace and tuyeres, which are connected to the heat exchanger at one end, in which, according to the invention, the afterburning chamber and the heat exchanger are equipped with heat-conducting plates installed parallel to each other at an angle to the horizon that does not exceed 45", the afterburning chamber is additionally equipped with a cover that covers the gap between the chamber and the bottom part, and the nozzles are connected directly to the furnace at the other end.

The heat exchange plates are attached spirally in the afterburning chamber to the common wall between the reactor and the afterburning chamber, and in the heat exchanger - to the wall between the afterburning chamber and the heat exchanger. Installation of such plates significantly increases the time and area of heat transfer from high-temperature afterburning products to waste and air.

The custom acts as a heat compensator during the thermal expansion of the wall between the afterburner chamber and the heat exchanger. The location of the nozzle inside the afterburning chamber solves the problem of air supply in excess at a ratio of 2.5-5 to the volume of pyrolysis gases and gaseous products of coke residue combustion. At such concentrations, the synthesis of furans and dioxins is impossible.

З For the possibility of visual control of the operation of the reactor during its operation (for example, the formation of a hot pillow) and to facilitate the implementation of preventive measures without stopping the entire installation (for example, cleaning the walls of the reactor from the soot of mineral fusible component waste, eliminating the plug and jams in the loading device in the event of an impact viscous, sticky or long-fibrous waste) and due to the absence of smoke and steam emissions from the upper part of the reactor, the end cover is hinged.

Air to support the combustion process is supplied directly to the furnace through nozzles installed in the bottom part. This supply of heated air ensures complete and uniform combustion over the entire section of the furnace. In the preferred option, the total area of the exit of the lances should be 5-20 95 of the cross-sectional area of the mine. The total area of the exit of the lances is less than 595 of the cross-sectional area of the furnace does not ensure the supply of the necessary amount of heated air for the combustion of coke residue, therefore the temperature in the combustion zones is insufficient to support the operation of the installation, there is a gradual decrease in temperature and a reduction in the volume of the reaction zone. The burning process turns into a smoldering process. Exceeding the exit area of the lances by more than 20 95 leads to the blowing of the combustion zone.

To ensure uniform decomposition of evaporation products, the depth of the furnace corresponds to the height of the combustion zone as 0.7-1.1. The depth of the pit is more than 1.1 times the height of the combustion zone, which means that the steam generated in the reactor is not exposed to high temperature, harmful organic vapors do not disintegrate and enter the environment, violating ecological and sanitary standards. The depth of the pit is less than 0.7 of the height of the combustion zone, which leads to underburning of the evaporation products, which also causes an increase in the number of harmful emissions into the environment.

To ensure the formation of draft, the installation contains a system of a chimney, a steam generator and a smoke extractor. Forced removal of post-combustion products contributes to a significant acceleration of the combustion process of pyrolysis gas, as it leads to a more complete and rapid supply of air to the post-combustion chamber. Due to the rapid supply of air, the reaction temperature rises.

An increase in the temperature of the afterburning reaction leads to the breakdown of harmful components of solid waste and contributes to an increase in the speed of reactions, and therefore the productivity of the installation as a whole.

To ensure the cleaning of the exhaust gases, the installation includes a system for cleaning the afterburning products. In the preferred version, a wet scrubber is used to ensure rapid cooling, "washing" of gases and neutralization of sulfur and chlorine.

Installing a smoke extractor on the scrubber ensures reliable removal of not only smoke from the combustion zone, but also vapors that are formed in the upper part of the reactor. Reliable removal of smoke and steam makes the installation environmentally safe.

To facilitate the creation of draft and to ensure a decrease in the temperature of the outgoing gases, a steam generator equipped with water inlet and steam outlet nozzles is installed in the chimney.

The evaporation of water at operating temperatures leads to the formation of superheated steam, which is ejected from the nozzle at a high speed and ejects smoke from the installation. At the same time, the efficiency may be sufficient to disable the smoke extractor. That is, the installation can work thanks to smoke extraction by ejection. In this way, the possibility of autonomous operation of the installation without the consumption of electricity is created.

To ensure uniform and unhindered removal of flue gases from the afterburner chamber, the chimney is installed at an angle of 3-507 to the horizon in the direction of smoke movement. An angle of inclination of the chimney of less than 3" leads to a significant resistance to the movement of gases, up to closing, so the evacuation system of afterburning products is disturbed, which leads to the need to install more powerful smoke extractors and the impossibility of autonomous operation on the steam ejector. An increase in the angle of inclination above 507" does not lead to an increase efficiency of the thermal operation of the reactor, however, the design of the scrubber installation is significantly complicated due to the need for its installation at a high altitude, which complicates its maintenance. In addition, due to the upward movement of the center of gravity, the structural stability of the entire installation decreases.

The location of the chimney tangentially in the direction of the movement of gases from the afterburning chamber contributes to the odden effect of the evacuation of flue gases from the installation, which in turn significantly reduces the load on the smoke extractor, therefore, the power of the engine can be reduced, and with the efficient operation of the steam generator, smoke removal can be carried out without a smoke extractor.

To ensure continuous operation, the loading device is located on the side of the reactor.

To ensure the complete completion of the afterburning process, the cross-sectional area of the chimney belongs to the area of the nozzles.

In the optimal version, the cross-sectional area of the chimney is 3-10 times larger than the exit area of the nozzles. The cross-sectional area of the chimney is less than the cross-sectional area of the tuyeres leads to the fact that the excess

Combustion products and steam formed during MSW drying in the reactor will be evacuated through the top of the reactor and the loading device into the environment. The steam generated in the drying process contains a large amount of harmful substances, therefore, the steam escaping outside the installation makes it non-compliant with sanitary standards. With a cross-sectional area of more than 10 tuyere cross-sections, too fast evacuation of post-combustion products occurs. At the same time, the speed of movement of the afterburning products is such that the heat exchange between the smoke and the wall of the heat exchanger is insufficient, the temperature of the gases entering the scrubber is very high (over 7007). Therefore, the time for gas cooling is insufficient to prevent the formation of new harmful compounds such as dioxin or furan. In addition, the water in the sump under the scrubber quickly heats up and boils. It should be noted that the afterburning process of pyrolysis gas and combustion products in the afterburning chamber does not have time to be completely completed, afterburning continues in the scrubber, so the efficiency of waste gas heat recovery is significantly reduced. In general, the thermal performance of the installation deteriorates.

The invention is explained by drawings, where

In fig. 1 shows the general view of the installation for disposal of solid household waste;

In fig. 2 shows the scheme of air supply and smoke removal in the installation;

In fig. C shows the part of the installation in the location of the custom in an enlarged view.

The installation for the disposal of solid household waste consists of a reactor 3, which is connected through a feeder 2 with a receiving hopper 1, an air heat exchanger 7 and an annular post-combustion chamber 5 between the reactor C and the heat exchanger 7. The post-combustion chamber 5 and the heat exchanger 7 are equipped with heat exchange plates 14, which are installed at a certain angle, and between them there is a partition 22. The thermal partition 22 is equipped with a sleeve 25, which forms a thermal compensator. Reactor C is equipped in the upper part with a hinged cover 4, and in the lower part - a platform 15 with a furnace 16. The post-combustion chamber 5 in the upper part is equipped with a chimney b containing a steam evaporator 8, which is equipped with steam outlet and water supply nozzles (not shown in the drawing). In the lower part of the smoke heat exchanger, a gap 23 is formed with reactor 3, furnace 16. Chimney 6 is connected to a wet scrubber 11, which is equipped with a smoke cleaner 10. The scrubber 11 in the lower part is equipped with a drain pipe 12 and a sump 21. Air heat exchanger 7 in the upper part equipped with nozzle 9 for air supply. The furnace 16 is lined in the bottom part 15 with a refractory lining 18. On the outside, reactor C and the bottom part 15 are covered with thermal insulation 13. In the lining 18, nozzles 17 are built in, which are connected at one end to the air heat exchanger 7, and at the other end to the lower part of the furnace 16. The furnace 16 is equipped in the lower part with a pipe 19, which goes into a sump 20, which acts as a hydraulic seal. Pipe 19 is equipped with an ignition nozzle 24.

The installation for disposal of solid household waste works as follows:

Combustible materials, such as wood, cardboard, oiled rags or coke, are loaded into the furnace 16. A burner is inserted into the ignition nozzle 24 and the combustible material is ignited with the flame of the burner from below. Gaseous combustion products from the furnace 16 enter the afterburning chamber 5 through the gap 23 due to the draft created by the chimney 10, where the heat from the combustion products is transferred through the heat exchange plates 14 to the wall of the reactor Z and the air heat exchanger 7. After the furnace 16 a red-hot pillow is formed (control of the formation of a red-hot pillow and control of the entire process is visually possible due to the hinged lid 4), waste begins to be fed: the waste is loaded into the receiving hopper 1 and pushed into the reactor 3 by the feeder 2. Through the reactor, the waste falls onto the red-hot pillow. The ignition nozzle is closed and air is started to be supplied through the air nozzle 9 to the air heat exchanger 7, where the air is heated (the measurements showed a temperature of 800--850 "C) and through the tuyeres 17 enters the furnace 16, and through the thermal compensator (formed by the thermal partition 22 and the 25) - into the afterburner chamber 5. In reactor C, the pyrolysis process begins as the temperature rises, as a result of which steam, pyrolysis gas and coke residue are formed.

Steam and pyrolysis gas, due to the draft created by the smoke extractor 10, enter the post-combustion chamber through the gap 23. In the post-combustion chamber 5, pyrolysis gas, steam and combustion products interact with the heated air and are combusted, as a result of which a large amount of heat is released. Afterburning products, rising up the spiral due to the location of the heat exchange plates 14 at a certain angle, which increases the time they stay in the chamber 5 and the completeness of heat transfer, transfer heat to the reactor C and the air heat exchanger 7 and through the chimney b enter the wet scrubber 11. Similarly, air through the nozzle 9, it moves down the spiral through the heat exchanger 7, gradually heating up. When entering the when mode

A large amount of gas is formed at the outlet, if necessary, water is supplied to the steam evaporator 8, and due to the creation of ejection, the draft in the afterburner chamber 5 is increased. In the wet scrubber 11, the outlet gas is quickly cooled to a temperature not higher than 150 "C and cleaned of impurities.

Wet cooling provides not only rapid cooling (253 s), which prevents the synthesis of dioxins and furans, but also washing of gas from sulfur, chlorine and dust. Purified steam and gas that meets sanitary and environmental standards enters the environment. The water flows through the pipe 12 into the sump 21, where it is filtered, cooled and fed back into the scrubber 11.

The coke residue is lowered into the furnace, where it interacts with the oxygen of the heated air and burns at a temperature of more than 1200 "C. The use of heated air raises the physical temperature of the combustion of the coke residue (temperature measurements showed 1400-1500 C), which ensures an increase in the heat load, the speed of the pyrolysis process and the performance of the installation as a whole.

Claims (10)

FORMULA OF THE INVENTION 1. Installation for the disposal of solid household waste, which contains a reactor and a bottom part, which are installed with a gap, coaxial with the reactor, an annular afterburner chamber, which is installed with the formation of a gap between it and the bottom part and has a common wall with the reactor and an annular heat exchanger, which has a common wall with the afterburning chamber, as well as furnaces and lances installed in the bottom part, which are connected at one end to the heat exchanger, which is distinguished by the fact that the afterburning chamber and the heat exchanger are equipped with heat-conducting plates installed parallel to each other at an angle to the horizon, which does not exceeds 45", the afterburning chamber is additionally equipped with a custom covering the gap between the chamber and the feed part, and the nozzles are connected directly to the furnace with the other end. 2. Installation according to claim 1, which differs in that the reactor is additionally equipped with a hinged lid. 3. Installation according to any of claims 1, 2, which is distinguished by the fact that it additionally contains a system for creating traction. 4. The installation according to claim 3, which differs in that the draft system consists of a chimney 60, a steam generator and a smoke extractor. 5. Installation according to any of claims 3-4, which differs in that the chimney is connected to the afterburning chamber. 6. Installation according to any of claims 1-5, which is characterized by the fact that it is additionally equipped with a gas cleaning system. 7. Installation according to point b, which differs in that the gas cleaning system contains a wet scrubber. 8. Installation according to any of claims 3-7, which differs in that the smoke extractor is installed on the scrubber. 9. Installation according to any of claims 3-7, which is characterized by the fact that the steam generator is installed in the chimney. 10. Installation according to any of claims 3-7 and 9, which differs in that the chimney is installed at an angle of 3-50" to the horizon in the direction of smoke movement from the afterburning chamber. y w 75 shi ! E : N ! N : y ! CAT K- t nn y He m en I E tu 21 glya. N ii KN Z EE CHE vek 3 i i OK y i ge ! sh- shi y OK v y ! and for a an EN Ko 5: ЕЙ KE No 7 и и и sa ! | ж. m She: SHK NE g Yan IZ OAE I shu - y ren zhenn nn: "Fig. 1