KR19980703226A - Household waste disposal method and apparatus - Google Patents

Abstract

In the method in which the material is pyrolyzed, a part of the pyrolysis gas from which the dust has been removed is burned, and the remaining gas is provided to the melting furnace 1. Hot gases generated in the combustion process are used to heat the pyrolysis reactor 2; The waste gas generated by heating the pyrolysis reactor 2 and the pyrolysis coke starts the melting process. The apparatus for treating household waste includes a pyrolysis reactor (2), a dust removal unit (5), a combustion chamber (6), a pyrolysis coke cooling unit (7), a metal separation unit (8), a grinding unit (9), It consists of the melting furnace 1, the secondary combustion chamber 10, the heat recovery unit 11, and the flue gas purification unit 12.

Description

Household waste disposal method and apparatus

The method of heat treating waste has been widely studied and discussed worldwide. Numerous publications published in the field are evidence of great interest in the method. Already in the early seventies, studies of pyrolysis methods for treating waste have been ongoing in various industrial countries. Pyrolysis methods have been used as an alternative to methods for treating industrial waste such as household waste and plastic waste, waste tires, and old cables. In particular, in the industrial countries such as Japan, the United States, the United Kingdom and Germany, 60 different pyrolysis methods have been studied.

DE-ZE: Umwelt Technologie Aktuell, S. 232-234 (1993) known melting apparatus. The main member of the melting apparatus is a vertical double jacket melting furnace with an outer jacket in which the cylindrical inner jacket is concentrically hung. Residue provided in the ring shaft between the two jackets is provided in the melting chamber, in which an oil ignited or gas ignited hot burner starts the melting process.

The present invention relates to a method and apparatus for treating household waste.

1 is a schematic diagram schematically showing a method according to the invention,

2 is a flow chart showing the progress of the method according to the invention,

3 is a flow chart showing how the material flows,

4 is a side view of the melting furnace,

5 is a chart showing the value of an eluate obtained from molten particles.

It is an object of the present invention to provide an environmentally friendly and economical method for household waste disposal.

The purpose is

a) pyrolysing the material,

b) removing dust from the pyrolysis gas, combusting a portion of the pyrolysis gas from which the dust has been removed, and providing the remaining pyrolysis gas into the melting furnace,

c) using hot gas from the combustion process to heat the pyrolysis gas,

d) by the method of domestic waste treatment, comprising the step of providing the waste gas from the heating process of the pyrolysis reactor and the pyrolysis coke to the melting process.

The present invention provides a complex pyrolysis-melting method for heat treating waste. An advantage of the process according to the invention is that the pyrolysis process and the melting process can be carried out separately. Thus, the methods can be made independently. The separation of these methods increases the availability. The method can be energy autonomous when using general household waste. The ash component and heavy metals are converted into leach resistant molten granules which can be used during melting. In the combined process, flue gas scrubbers without waste water are used. The combined method is operated at normal pressure. No external heating or additional heating is necessary. There is no need to use technical oxygen to increase the energy yield of the individual processes.

The generation of dibenzodioxin and dibenzofuran can be prevented by not adding air at the time of pyrolysis. The heating of the pyrolysis drum is made by burning pyrolysis gas. In pyrolysis, different wastes can be used, such as household waste, special waste, waste tires, shredding residues. Pyrolysis products such as coke, oil and gas may be separated, stored, used or incinerated. Pyrolysis is set such that the materials used vary both quantitatively and qualitatively.

At the time of melting, coke is not powdered. The melting apparatus can be started and run more quickly. Additional calorie wastes such as spent HOK, dried sewage sludge and special wastes in the liquid state can be provided. Heat retaining materials have a long lifespan. Flexible partial load methods are possible. The combustion process is staged in the primary and secondary chambers, resulting in low NO _x values in the waste gas. There is only a very small amount of residual dust in the waste gas.

A preferred embodiment of the invention is to pretreat the material before pyrolysis. This measure yields a high quality pyrolysis product.

A preferred embodiment of the present invention is to grind and compress the material to a size of 1000 mm prior to pyrolysis to provide it through the one shaft into the pyrolysis reactor. By this measure, pyrolysis can be made economically.

In a preferred embodiment of the invention, the material is ground to a size of 300 mm prior to pyrolysis and provided by the pressing worm into the pyrolysis reactor. By this measure, pyrolysis can be made very economically.

A preferred embodiment of the invention is to separate the material from the metal containing material prior to pyrolysis. Separation of the metal can be made very efficiently. The metal separation has an effect on reducing the capacity required for the pyrolysis drum.

A preferred embodiment of the present invention is to use an indirect heated pyrolysis drum as a pyrolysis reactor. By this measure, the operating cost of pyrolysis can be greatly reduced.

A preferred embodiment of the present invention is that the heat required to heat the pyrolysis reactor is obtained by the waste gas from the combustion process according to process step (b) and from part of the furnace waste gas. By this measure the pyrolysis drum is operated very economically.

In a preferred embodiment of the invention, the process of removing dust from the pyrolysis gas is carried out above the melting point of water in the oil-cooling apparatus. By this measure, dust can be removed very well from the pyrolysis gas.

In a preferred embodiment of the present invention, the pyrolysis coke is cooled, separated from the metal containing material and ground to a particle size of 50 mm, and then 50 mm particles are provided to the melting furnace. By this measure the furnace is operated very economically.

Preferred embodiments of the invention are 50 mm in size and contain calories such as dried sewage sludge, pyrolysis gas, residues from oil-cooling units, heated oils, plastics, pastes, liquid and gaseous heatable wastes. It is to provide pyrolysis coke and coke in the melting furnace containing sufficient waste and components such as spent carbon. By this measure, a substance with sufficient calories is used effectively as fuel, which is disposed of economically and environmentally friendly by the method according to the invention.

A preferred embodiment of the present invention is to provide combusted waste gas from a melting furnace into a boiler and / or a once-through heat exchanger. By the above measures, the energy of the waste gas can be very usefully used.

A preferred embodiment of the present invention is to refeed dust from the dust separation process of the melting method into the melting furnace. By this measure, the separated dust can be fed back into the melting apparatus, eliminating the need for cost-intensive incineration.

In accordance with the present invention for the treatment of household waste, the pyrolysis reactor, dust removal unit, combustion chamber, pyrolysis coke cooling unit, metal separation unit, grinding unit, melting furnace, secondary combustion chamber, heat recovery unit and flue gas purification unit A device is provided.

An apparatus for thermally incineration and use of household waste is used in accordance with the present invention simultaneously with the formation of reusable molten granules in which the eluate is fixed.

A pyrolysis gas, pyrolysis coke and / or pyrolysis dust is provided from the pyrolysis furnace, the at least one burner facing the surface of the material to be melted, disposed in the furnace cover of the primary chamber, In a melting furnace configured to provide tertiary air into the primary chamber, pyrolysis coke and / or pyrolysis dust is treated within the scope of an embodiment of the method according to the invention, in which case the material and pyrolysis gas to be melted are The molten material provided in and circulating leaves the primary chamber with flue gas, which is passed through the secondary chamber and discharged as waste.

The temperature in the primary chamber is 1,250-1,500 ° C.

The invention is explained in detail below with reference to the drawings.

According to the diagram shown in FIG. 1 and the flowchart shown in FIG. 2, the transport vehicle transports household waste to an external processing device in the waste bunker 11 without intermediate connection. Garbage is pulverized into particles of 300 mm size in the grinding unit 13. The crushed garbage is sent into the pyrolysis drum 2. The pyrolysis drum 2 is continuously heated directly through the outer wall by the pyrolysis gas from which dust is removed and reburned. The temperature of the reburned pyrolysis gas is optionally set such that the softening point of the dust particles is not exceeded. The cooled waste gas is suction-filtered from the drum wall by a cooling fan and supplied to the steam generator 3. The pyrolysis coke is led from a pyrolysis drum 2 having a temperature of about 500 ° C. to a pyrolysis coke cooling unit 7 (wet slag remover), where the pyrolysis coke is cooled. The wet slag remover 7 seals the outlet of the pyrolysis drum 2 to the atmosphere. Thereby the NE-metal and iron are separated from the cooled pyrolysis coke in the metal separation unit 8, and then the pyrolysis coke is provided in the melting furnace 1. The pyrolysis coke is pulverized in the grinding unit 9 before being sent into the melting furnace 1. The pyrolysis gas is dedusted in the oil-cooling device 5 and reburned in the combustion chamber 6. The excess pyrolysis gas can be combusted in the furnace 1. The oil 5 coming from the oil-cooling device comprises completely condensed pyrolysis oil and completely discharged dust. An oil treatment unit, centrifuge or decanter is used to separate the dust from the circulating oil. The condensed oil / dust particles are introduced into the melting furnace 1 through a window burner. Pyrolysis coke is provided in the primary chamber 17 of the furnace 1 with a particle size of 50 mm. The combustion of the coke and the melting of the ash components are energy autonomous by preheated air. Liquid sludge flows through the central outlet 18 from the primary chamber 17 and passes through the secondary chamber 21 into the water bath of the wet sludge remover 22. Liquid sludge solidifies into particles in the form of glass in a water bath. The waste gas is set to contain air at least 6 Vol% O ₂ in the secondary chamber 21. The waste gas formed from the melting furnace 1 and the cooled and burned pyrolysis gas from the pyrolysis chamber are commonly supplied to the pyrolysis apparatus, ie, the boiler, via the second combustion chamber 10. The boiler 3 consists of a radiator and a convection section with an integrated air preheater. Cooling waste gas then reaches the flue gas purification device 12. In the flue gas purification apparatus, HCL and SO ₂ dust is separated from the flue gas removed by a two-step wet purge process. Subsequently, in the Hg-separation process functioning by the Sorbalit method, HOK method or similar method, the residue of basic Hg or HCL, SO ₂ and hydrocarbons are separated. In the Sorbalit method, the spent activated carbon / Ca (OH) ₂ mixture is provided in the melting furnace 1. Separation of Hg takes place during HCL purification.

The mass flow and method data of the method according to the invention can be seen from the flow chart shown in FIG. 3. The pyrolysis gas leaves the pyrolysis drum having a temperature of 500 ° C. The amount of contaminated gas (H ₂ S, COS, HCL) can be minimized by adding lime into the pyrolysis drum. Pyrolysis gases consist of CO, CO ₂ or higher hydrocarbons in addition to evaporated water. When cooling to 150 ° C. in the oil-cooling device 5, about 40 kg of pyrolysis oil per 1 tonne of waste used is fully condensed. The discharge of dust is 20 to 30 g / m ³ . Flammable dust and pyrolysis oil are separated in the oil-cooling device 5. Most of the pyrolysis gas is burned in the combustion chamber 6 with a hot gas provided inside the outer jacket of the pyrolysis drum 2 having a temperature of 1,050 ° C to 1,250 ° C, at a temperature of 550 ° C to 600 ° C. Cooling of the pyrolysis gas takes place. The remaining pyrolysis gas of about 30 Vol% is provided directly into the furnace 1.

Pyrolysis coke consists of about 18% to 20% by weight of carbon. The remaining components are ash, nonferrous and iron. The pyrolysis coke reaches a temperature of 500 ° C. in the pyrolysis drum 2. The pyrolysis coke is cooled to about 60 ° C. to 70 ° C. in a wet sludge remover 7 connected later. The released pyrolysis coke is then NE-separated and Fe-separated, at which time a useful material is obtained. Pyrolysis coke is provided in the melting furnace 1 with a particle size of 50 mm. Pyrolysis coke is pre-powdered, which is not usually necessary. The ash component is melted in the melting furnace 1 at a temperature of about 1,350 ° C. Heavy metals are combined into a stable matrix of aluminum silicates. The liquid sludge becomes glass free leaching prevention granules in the water tank of the wet sludge remover 22. The waste gas leaves the primary chamber 17 of the furnace 1 at a temperature of about 1,350 ° C. By adding air, the oxygen content in the secondary chamber 21 of the melting furnace 1 is set to 6 Vol% to 7 Vol%. By adding air and evaporating water from the wet sludge remover 22, the waste gas is cooled to a temperature of 950 ° C to 1,150 ° C. Evaporated heavy metal and alkali metal compounds from the primary chamber 17 are fully condensed and discharged as residual dust. The composition of the waste gas coming from the boiler 3 almost matches the composition of the flue gas coming from a conventional burner.

The melting furnace principle of the present invention becomes clear from the side view of the melting furnace 1 shown in FIG. The furnace 1 is a portable furnace cover 14, a double shuttle valve 15, at least one burner 16, a primary chamber 17, a sludge discharger 18, a hydraulic furnace driver 19, a video furnace A monitor 20, a secondary chamber 21 and a wet sludge remover 22.

The method and apparatus according to the invention are used for the disposal of household waste.

Claims (16)

a) pyrolysing the material, b) removing dust from the pyrolysis gas, combusting a portion of the pyrolysis gas from which the dust has been removed, and providing the remaining pyrolysis gas into the melting furnace 1, c) using a hot gas from the combustion process to heat the pyrolysis gas, d) A method of treating household waste, comprising the step of providing the waste gas from the heating process of the pyrolysis reactor (2) and the pyrolysis coke to a melting process. The method of claim 1 wherein the material is pretreated prior to pyrolysis. 3. Process according to claim 2, characterized in that the material is ground and compressed to a size of 1,000 mm and provided in the pyrolysis reactor (2) through one shaft. 3. Process according to claim 2, characterized in that the material is ground to a size of 300 mm and provided by the pressing worm into the pyrolysis reactor (2). 5. The method of claim 2, wherein the material is separated from the material containing the metal. Process according to claims 1 to 5, characterized in that an indirectly heated pyrolysis drum is used as the pyrolysis reactor (2). 7. Process according to claims 1 to 6, characterized in that the heat required to heat the pyrolysis reactor (2) is obtained by waste gas from the combustion process according to process step (b) and from some waste gas in the furnace. 8. Process according to claim 1, characterized in that the process of removing dust from the pyrolysis gas is carried out above the melting point of water in the oil-cooling device (5). The method according to any one of claims 1 to 8, wherein the cooled pyrolysis coke separated and filtered from the material containing the metal is ground to a particle size of 50 mm and the particles of 50 mm size are supplied to the melting furnace 1. Characterized in that the method. 10. The process of Claims 1 to 9, which is 50 mm in size, such as dried sewage sludge, pyrolysis gas, residues from oil-cooling units, heated oils, plastics, pastes, liquid and gaseous heatable wastes. A method of providing a melting furnace (1) with pyrolysis coke and coke comprising wastes with sufficient calories and constituents such as spent carbon. Method according to one of the preceding claims, characterized in that the combusted waste gas is provided from the furnace (1) into the boiler (3) and / or the once-through heat exchanger (4). The method according to claim 1 to 11, characterized in that the dust from the dust removal step of the melting method is resupplied to the melting furnace (1). Pyrolysis reactor (2), dust removal unit (5), combustion chamber (6), pyrolysis coke cooling unit (7), metal separation unit (8), grinding unit (9), melting furnace (1), secondary combustion chamber (10) A household waste disposal apparatus comprising a heat recovery unit (11) and a flue gas purification unit. Use of the apparatus according to claim 13, wherein the eluate is used for thermally incineration and utilization of household waste at the same time as the reusable molten granules are formed. a) providing the primary chamber 18 with material to be melted, b) providing pyrolysis gas to the primary chamber 17, c) circulating molten material leaves the primary chamber 17 with flue gas, and the molten material is discharged as sludge past the secondary chamber 21, A pyrolysis gas, pyrolysis coke and / or pyrolysis dust provided from the pyrolysis furnace 2 comprising at least one burner 16 facing the surface of the material to be melted, arranged in the furnace lid of the primary chamber 17. And pyrolysis coke and / or pyrolysis dust in a melting furnace (1) configured to provide tertiary air to the primary chamber (17) at one or more locations in the furnace lid. 16. The method of claim 15, wherein the temperature in the primary chamber (17) is between 1,250 and 1,500 ° C.