KR100581509B1 - Method for improving properties of combustion residues produced by combustion plant, and method for treatment of the residues - Google Patents

Abstract

Combustion control system so that the combustion residue is pre-sintered and / or melted on the fuel layer of the main combustion zone in advance to the main circuit, and the molten or unsintered residue is extruded to the outside at the end of the combustion process and then returned to the combustion process. Works. In addition, the wet combustion residue taken out from the wet extraction apparatus is first separated into two classifications by a mechanical separation step, and then the main classification consisting essentially of coarse and oversized classifications is extracted from the wet extraction apparatus. Rinse with rinsed water to separate the small particles attached to the combustion residue.

Description

METHOD FOR IMPROVING PROPERTIES OF COMBUSTION RESIDUES PRODUCED BY COMBUSTION PLANT, AND METHOD FOR TREATMENT OF THE RESIDUES

The present invention relates to a method for improving the characteristics of combustion residues produced in combustion plants, in particular waste / energy conversion plants, which burn fuel on a combustion grate and raise the temperature of the combustion residues generated under appropriate fuel control.

In addition, the present invention is produced by a combustion plant, in particular a waste incineration unit, which burns fuel on a combustion grate, quenches the combustion residues generated in a wet extraction apparatus, and then transfers them outward from the wet extraction apparatus. The present invention relates to a method for treating combustion residues.

In addition, the present invention relates to a process for treating combustion residues produced in a combustion plant, in particular a waste / energy conversion plant, which burns fuel on a combustion grate and raises the temperature of the combustion residues generated under appropriate fuel control.

In a method of the kind known by EP 0 667 490 B1, the fuel has a temperature below the main melting point before the bottom ash generated by combustion proceeds to the external melting stage of the combustion grate. Heated on the combustion grate to a degree. This method regulates the combustion so that the temperature of the bottom residue at the grate end is as high as possible in order to keep the amount of energy required for the downstream melting step as low as possible. At this time, however, sintering or melting of the circumference does not occur. Nevertheless, in order to obtain the required turn characteristics, a downstream melting step is required. This downstream melting step not only requires the relevant equipment, but also requires an increased amount of energy in spite of the previously mentioned heating operation.

Inorganic and organic contaminants from waste are important factors in the required turn characteristics. In particular, heavy metals and salts are major inorganic contaminants. Organic contaminants are particularly caused by incomplete combustion. In addition, when evaluating rounding characteristics, it is important how many contaminants are eluted during the dissolution test. In addition, the mechanical properties of the week are important when assessing the suitability for use in construction work such as landfills, civil works, and road works.

Due to the high temperatures involved in the treatment of the combustion residues in the melting stage, the molten combustion residues are characterized by a low proportion of organic compounds. Representative ashes emitted from the waste / energy conversion plant typically contain 1% -5% of the unburnt amount measured as the loss of ignition, whereas the loss of ignition of the molten combustion residue is less than 0.3% by weight. In addition, the molten combustion residues are characterized by a low ratio of eluted salts and heavy metals. This is because these salts and heavy metals are integrated in a glass mold formed when the salts and heavy metals evaporate or the melt is cooled.

On the other hand, German Patent No. 701 606 C transfers a combustion residue to a discharge device having an outlet and suction portion having an upward outlet chute, and transfers the residue from the discharge device by using a discharge ram. Discharging technology is disclosed. These combustion residues are called rounds. Water to quench the circumference is supplied to the outlet. Only enough fresh water is introduced into the barrel to compensate for the amount of water discharged with the wet circumference. The concentrations of various substances and compounds, such as salts, attached to the residue become stable, and as a result, their concentration cannot be reduced. The characteristics of the suitability of a weekly landfill and reclaimed civil engineering material are unsatisfactory. The fact that the residues are not separated (classified) into classifications with better and poorer properties is the reason for this drawback. As a result, the entire combustion residue inevitably exhibits unsatisfactory characteristics.

In addition, German Patent No. 4 423 927 discloses a technique for coarse cleaning by transferring residues generated from a furnace directly to a water bath without conventional quenching. The dry, roughly cleaned circumference is separated into two or more classifications. All particles smaller than 2 mm are assigned to the first classification and other particles are assigned to the second classification. Next, the method continues so that the second classification is separated into two or more portions through a screening step. All particles smaller than 27 mm-35 mm are assigned to the third classification. The remaining particles are assigned to the fourth classification. In this way, a residue classification having satisfactory properties is obtained. However, the disadvantages of such a method are that a wide range of dust is generated and problems related to the intervening air from the furnace.

The present invention has been raised in view of the above-described problems with the prior art.

In the present invention, it is an object of the first group of inventions to provide a method by which the combustion process can be controlled so that a complete sintering round having the required properties can be obtained without the use of downstream melting or vitrification units.

In addition, in the present invention, the object of the second group of inventions is to separate the classifiers having good characteristics, to solve the problems associated with the generation of dust and the intervening air from the furnace, and additionally the consumption of water. It is to provide a method that can reduce the.

In addition, in the present invention, the object of the third group of inventions is to control the combustion process so that a complete sintering round having the required characteristics can be obtained without using downstream melting or vitrification units, and using minimal devices. Therefore, it is possible to solve the problems related to the generation of dust and the intervening air from fire, and to provide a method for further reducing the consumption of water.

A method for improving the characteristics of combustion residues produced in a combustion plant, and a method for treating residues according to the present invention will be described in the following embodiments with reference to the accompanying drawings.

Method for improving the characteristics of combustion residues produced in the combustion plant according to the invention of the first group

The object of the first group of invention is to sinter and / or melt the combustion residue in the main circuit in the fuel layer of the main combustion zone in advance, and to extinguish the combustion residue that has not yet been melted or sintered at the end of the combustion process and then again to the combustion process. Is achieved by operating the combustion control system.

In other words, the invention of the first group is based on first performing a grating combustion process so that sintering or melting occurs in advance in the fuel layer of the main combustion zone, and secondly, two or three times to perform necessary sintering and / or melting. It is based on conveying combustion residues that have not yet been sintered or melted so that levels can be obtained.

In the first group of inventions, the term "complete sintering round" means a material consisting of a sintered and / or molten mass having, for example, a particle size of at least 8 mm. These agglomerates consist of combustion residues from the waste agglomerated through total melting or surface melting.

The sintered and / or molten mass preferably has a porous structure due to gas leakage during sintering or melting. The possible porosity of the complete sintering cycle is not high enough to produce a sufficiently low viscosity of the molten ash on the fuel layer, and after the gas bubbles are removed by a process similar to the known bubble removal process in glass production. It is the result of the phenomenon of leaving holes. Differences exist between the normal vitrification and complete sintering cycles obtained by downstream high temperature treatment methods using refractory-lined crucible furnaces or other melting units.

Waste components, such as glass or metal, that pass through the grate substantially unaffected by the combustion process, are not strictly melted or sintered on the fuel bed. However, complete sintering can contain such glass or metal. These components have essential features for combustion or elution contaminants.

In Hammelli (Muell und Abfall 31, Supplement on Disposal of Bottom Ash and Other Residues, page 142, 1994). , The term "sintering" is described as "special case of melting and solidification." Thus, the term "sintering" used hereinafter as the meaning of "surface melting of particles or mutual melting of particles" is mainly used. In some cases, the sinter produced by the sintering of complete sintering can melt in whole or in part.

The rolling component that does not sinter and / or melt is defined as the residual rolling. Residual circumference, as compared to complete sintering circumference, is characterized by a small particle size, high loss on ignition, and a high rate of eluting contaminants.

The invention of the first group has focused on sintering and / or melting the combustion residue on the fuel layer of the main combustion zone which has not been considered so far. In practice, if a liquid round is produced between the individual grate bars or between the moving parts of the grate, it is very detrimental to the mechanical part of the combustion grate. For this reason, melting of the fly ash on the grate was avoided and care must be taken to ensure that the melting point of the fly ash does not reach the fuel bed.

In the first group of methods of the invention, the sintering and / or melting process takes place in the upper fuel layer. The reason is that the maximum heat shock occurs from the top through the radiation of the flame, and the heating from the downward direction, where the temperature of the material located directly on the grate, is cooler (in a relative sense) than in the normal case of the fuel layer. This is because it can be kept lower from below by adding the air. When regulating combustion in this manner, since not all combustion residues can be converted to a fully sintered main circuit having the necessary characteristics, combustion residues which do not yet have the characteristics of a complete sintered cycle are returned to the combustion process.

No additional external energy source is needed to achieve the sintering and / or melting process on the fuel bed. The properties of the circumference obtained are very similar to those of the circumference obtained by the product produced by the downstream thermal high temperature process for melting and vitrification known to those skilled in the art. Units such as rotary kilns, crucible furnaces, and melting chambers are used. However, a major disadvantage of these known methods is that they require very complex additional units and consume high energy. The invention of the first group solves this problem and can produce a circumference having characteristics substantially similar to the circumference obtained by a known method.

According to a quite advantageous embodiment of the combustion control system according to the method of the first group of invention, the heating air from below is combusted so that the oxygen content is about 25-40 vol%, preferably 25-30 vol%. Depending on the characteristics of the waste (garbage characteristics), oxygen is enriched. Furthermore, according to a further advantageous embodiment, the heating air from the downward direction is preheated to about 100-400 ° C. These shapes may be used alone or together depending on the situation. The temperature of the fuel bed (generally the waste bed), which is a function of the fuel characteristics, is preferably set at 1000-1400 ° C.

All combustion controls to achieve the desired conditions in which combustion residues are converted to sintering and / or molten mains, have a specific proportion (eg, about 25% to 75% by weight of the total amount of combustion residues). Selected to be provided. In this way, there is a sufficient amount of non-melting material to surround the molten ash on the fuel bed of the main combustion zone, thus not adversely affecting the mechanical part of the grate.

In a further advantageous embodiment of the invention, fly ash is returned to the combustion process. This fly ash leaves the fuel bed with the combustion gases and enters the flue gas filter downstream via the boiler.

Incomplete sintering and complete sintering may be separated from the combustion system after exiting the combustion system (eg, via a sieve of a particle size of 2 mm-10 mm). Oversize is a complete sinter round, and undersize is a classification to be returned. Various mechanical separation methods exist for carrying out such separation processes that are familiar to those skilled in the art.

Separation may be generated by screening or by a combination of screening and washing steps as described in another advantageous embodiment of the present invention.

Of course, there are other ways to improve the circumferential properties that occur outside the combustion plant, and this method is particularly observed in special cleaning processes that do not use chemical additives.

The fines having a particle size of less than 2 mm-10 mm are returned to the combustion process. This conveyance can be effected by adding the microclassified fuel to the supplied fuel or by feeding the microclassified directly to the fuel layer. In order to avoid the deposition of dust and to provide easy handling, it is appropriate that the microparticle portion is granulated or refined before being returned.

Method for treating combustion residues produced in a combustion plant according to the invention of the second group

The object of the second group of inventions is achieved by the technical features described below on the basis of two different procedures.

The first process consists of mechanically separating wet combusted residues from the wet discharge apparatus into two classifications. The main classification consists essentially of coarse and oversized classifications. This main fraction is rinsed with the water discharged from the wet brewing device to separate the finer particles attached to the combustion residue, and the washing water is transferred to the wet brewing device together with the finer parts separated in the washing step.

If the water generated in the wet extraction device is circulated in this manner, it is possible to clean the main classification having good characteristics without the need to use a large amount of fresh water. Experience has shown that the fraction of microparticles attached to the combustion residues adversely affects the properties of the main classification. Therefore, the combustion residue from which the fine particle portion has been washed out has good characteristics and can be effectively used as a rejuvenation circumference, for example, a civil engineering material.

The second process consists of the step of mechanically separating the wet combustion residues generated from the wet discharge device into two classifications. The main classification consists essentially of coarse and oversized classifications. This main fraction is first pulverized and then rinsed with water discharged from the wet brewing apparatus to separate the microparticle fraction attached to the pulverized combustion residue, and the washing water together with the microparticle fraction separated in the washing step. It is transferred to a wet drawer.

The second procedure has the advantage that, before cleaning, there are no contaminants contained in the main classification. In this way, these contained contaminants are removed in the cleaning step. Another advantage is that the ground material, which improves the cleaning efficiency, has a larger surface. This advantage is particularly important due to the porous form of the material obtained from the main classification. The second process is used when very high characteristics of the combustion residue are required, when the main classification has many contaminants, or when the porosity of the combustion residue is important. The second process is also used when the main feed of the week is further ground in subsequent processing steps. For example, it is advantageous to use the second procedure when the main class of liquor (final product) has to be ground in the dissolution test to determine the characteristics of the combustion residue. The pulverized and cleaned main fraction should not be confused with the microclassification. In most cases, since the main classification is melted or sintered, the content of unburned contaminants or eluting contaminants is low, so these properties do not change by grinding. Thus, the main classifier comminuted according to the second process has very different characteristics compared to the main microclassifier having the high content of the above-mentioned contaminants.

According to one embodiment of the second group of inventions, the ultrafines and microclassifieds generated during the mechanical separation are transferred (circulated) to the combustion process. These classifications are subjected to the combustion process once more, so that these classifications can be melted and sintered.

These methods alleviate the disadvantages of the prior art process described first, as all combustion residues are transported for regeneration, even if a small amount of residues with poor properties are contained. Compared with the second method described in the prior art, the disadvantage that dust is generated and the furnace is sealed is eliminated. In addition, by conveying the ultrafines and the fines having poor properties, the ratio of the reproducible combustion residues is further increased because, after the conveyed microparticle portion is first conveyed or repeatedly conveyed, This is because there is an opportunity to lump into combustion residues with desirable properties. Since nothing is returned to the combustion process, the second method of the prior art described does not have this advantage.

According to another embodiment according to the first process or the second process of the second group of invention, the main class fraction pre-washed with water from the wet extractor is cleaned with fresh water and carries a relatively large amount of contaminants. The water in the tooth is washed away, resulting in further improvements in combustion residues and / or sintering cycles. Since fresh water is used to clean the coarse classification, this embodiment has the advantage that a certain proportion of the water resulting from the cleaning can be transferred to a flue gas cleaning system that does not need to be cleaned in advance because the water This is because the proportion of the contaminants contained therein is relatively low. In addition, this embodiment provides the advantage that a certain proportion of the water resulting from the cleaning can be supplied to the wet brewing device. The level of the drawing device can be maintained in this way. Since water is constantly transported out along with the discharged combustion residue, the water level in the drawing device is lowered. In some cases, the water level should be high. Since the water resulting from the cleaning has negligible amounts of calcium and sulfur, there is no risk of clogging the pipes and nozzles.

According to a second process according to the invention of the second group, after the first separation step has been carried out, even if the main classification contains a high proportion of oversized classification (generally contains many waste metals), the present invention In the mechanical separation step according to another embodiment of the oversized coarse fraction is further separated. The metal is separated by a magnetic separator.

In embodiments of the second group of inventions, for example, the particle size is less than 2 mm for ultrafines, at least 2 mm for fines, less than 8 mm, at least 8 mm for coarse, 32 less than mm, and at least 32 mm for oversize classification. These values are provided to serve as a guide to better understanding the invention. Obviously, each classifier contains a negligible amount of incidental, smaller classifiers.

In general, it is preferred that the microclassify, which occurs directly from the extraction device and has a particle size of less than about 8 mm, is conveyed to the combustion process because of its undesirable properties. In the second process, a pulverized main classification having a particle size comparable to that of the microclassification is produced, and this classification can be used as a building material because the pulverized main classification has much better properties.

For example, in the second process, if a break point of 32 mm is observed for the first coarse separation step, i.e. if an oversize classification is separated, the second mechanical step with a break point of 8 mm It is preferred that all parts of less than 8 mm conveyed to the combustion process be provided.

According to another embodiment of the second group of inventions, to obtain as large a recycling classification as possible, the coarse classification separated from the main classification may be carried out in a size reduction step (crusher, rock drill, etc.) for the oversize classification. Mixed with the pulverized combustion residue produced). In this case, particles of particle size which are not preferable for regeneration, specifically particles of particle size to be conveyed in the combustion process, are generated during the size reduction, so that they are mechanically separated from the first mixed classification obtained by the above mixing. It is desirable to remove particles of undesired particle size by carrying out.

If combustion residues are to be produced for certain applications, such as road construction flooring, this material should have compressibility. It is virtually impossible to obtain such compressibility without a microclassifier (eg having a particle size of at least 2 mm and less than 8 mm as described above). For that reason, it is desirable that some of the coarse fractions undergo a size reduction step in order to intentionally obtain these necessary microclasses. Therefore, it is preferable that the above-mentioned fine fraction of the particle size is contained in this ratio. Advantageously, about 30% by weight coarse fraction is subjected to this size reduction step. The resulting fine and ultrafine classifications are mixed with the coarse classification to form a second mixed classification. Preferably, 70% by weight of the mixed classification used for road construction consists of coarse classification.

In this second mixed classification, the dominant particle size is larger than 8 mm and it has been found that these components have the necessary properties for regeneration. However, in order to secure the compressive formability of the above-mentioned road construction residue, a low ratio classification having a particle size of 2 mm or more and less than 8 mm is also required.

According to yet another embodiment of the second group of inventions, the second mixed fraction is washed with water from the wet extraction device and the first mixed fraction is separated. In this case, parts having a particle size of less than 2 mm, mainly containing particularly serious contaminants, can be reliably separated from the renewable residue.

As already described in another document, this washing water can be advantageously transferred to a wet retractor. By returning water in this manner, the consumption of fresh water can be reduced as much as possible.

The separated metal is preferably cleaned using water from the extraction device so that the stuck combustion residues can be washed off. Advantageously, a screening step is used to mechanically separate the classification.

Adding a precipitant for soluble heavy metals to the water of the drawer is very helpful in increasing the properties of the regenerated combustion residue. As a result, these heavy metals can be separated by the addition of precipitants.

Method for treating combustion residues generated in the combustion plant according to the third group of the invention

The above object is achieved by the method of the third group of inventions described below on the basis of two different methods.

According to the first method according to the present invention, a combustion control system in which combustion residues are sintered and / or melted in the main circuit in advance in the fuel layer of the main combustion zone is operated, and the entirety of the combustion residues is quenched by a wet recirculation apparatus and then wetted. Discharged from the drawer to the outside, the wet combustion residue discharged from the wet drawer is separated into two classifications through a mechanical separation step, and then essentially composed of coarse and oversized classifications. The main classification is washed with water discharged from the wet extraction device to separate the finer parts attached to the combustion residue, and the washing water is transferred to the wet extraction device together with the finer parts separated in the cleaning step.

This first method is useful when the renewable main classifier contains an insignificant proportion of contaminants that can be washed away by washing, for example salts or heavy metals.

The third group of inventions mainly has two technical features. The first technical feature includes a combustion control system, and the second technical feature includes mechanical treatment of residues generated by the combustion process. Among these features, the second technical feature includes two different methods depending on the fuel composition.

The combustion control included in the first technical feature is common to the following two methods according to the mechanical treatment of the residue, by generating sintering or melting on the grate of the main combustion zone, and conveying the combustion residue which is not yet sintered or melted, It is based on the combustion process on the grate performed to achieve the required level of sintering and / or melting in two or three trials.

The term "complete sintering round" means a material consisting of a sintered and / or molten mass having, for example, a particle size of at least 8 mm. These agglomerates consist of combustion residues obtained from waste agglomerated through total melting or surface melting.

The sintered and / or molten masses preferably have a porous structure due to gas leakage during sintering or melting. The possible porosity of the complete sintering circle is not high enough to produce a sufficiently low viscosity of the molten ash on the fuel layer, leaving holes after the gas bubbles have been removed by a process similar to the bubble removal process publicly known for glass making. The result of the phenomenon. There is a difference between the general vitrification circumference and the complete sintering circumference obtained by the crucible of the refractory line or by a downstream high temperature treatment method using another melting unit.

Waste components, such as glass or metal, that pass through the grate substantially unaffected by the combustion process, are not strictly melted or sintered on the fuel bed. However, complete sintering can contain such glass or metal. These components have essential features for post combustion and elution contaminants.

In the literature (previously described Hammeli), the term "sintering" is described as "special case of melting and coagulation". Therefore, the term "sintering" used hereinafter as the meaning of "surface melting of particles or mutual melting of particles" may deviate mainly from general scientific interpretation. The agglomerates generated by sintering of the complete sintering can be melted in whole or in part.

The rolling component that does not sinter and / or melt is defined as the residual rolling. Residual circumference, as compared to complete sintering circumference, is characterized by a small particle size, high loss on ignition, and a high rate of eluting contaminants.

The present invention focuses on sintering and / or melting the combustion residue on the fuel layer of the main combustion zone which has not been considered so far. In practice, if a liquid turn is produced between the individual grate bars or between the moving parts of the grate, the mechanical parts of the combustion grate are very adversely affected. For this reason, melting of the fly ash on the grate was avoided and care must be taken to ensure that the melting point of the fly ash does not reach the fuel bed.

In the method of the third group of invention, the sintering and / or melting process takes place in the upper fuel layer. The reason is that the maximum heat shock occurs from the top through the radiation of the flame, and the heating from the downward direction, where the temperature of the material located directly on the grate, is cooler (in a relative sense) than in the normal case of the fuel layer. By adding solvent air it can be kept lower from below. When regulating combustion in this manner, since not all combustion residues can be converted to a fully sintered main circuit with the required quality, combustion residues that do not yet have the characteristics of a complete sintered cycle are returned to the combustion process.

No additional external energy source is needed to achieve the sintering and / or melting process on the fuel bed. The characteristics of the circumference obtained are very similar to those of the circumference obtained by the product produced by the downstream thermal high temperature process for melting and vitrification well known to those skilled in the art. Units such as rotary kilns, crucible furnaces, and melting chambers are used. However, a major disadvantage of these known methods is that they require very complex additional units and consume high energy. The invention of the third group solves this problem and can produce a circumference having characteristics substantially similar to the circumference obtained by a known method.

In the above-described first method related to the mechanical treatment, when the water generated in the wet discharge device is circulated, the main classification product having good characteristics can be washed without using a large amount of fresh water. Experience has shown that the fraction of microparticles attached to the combustion residues adversely affects the properties of the main classification. Therefore, the combustion residue from which the fine particle portion has been washed out has good characteristics and can be effectively used as a revolving spinneret.

In a second method suitable for the treatment of combustion residues containing many contaminants that can be washed off, for example salts or heavy metals, the aim is that the combustion residues are sintered and / or melted in advance on the fuel bed of the main combustion zone in advance. Operate the combustion control system as much as possible, quench the entirety of the combustion residues generated in the wet brewing apparatus, then discharge them in the brewing apparatus, and wet combustible residues from the wet brewing apparatus into two classifications through the mechanical separation step. Firstly (separated main class consisting essentially of coarse and oversized classifiers is subjected to a size reduction step and subsequently rinsed with water discharged from the wet brewing device), and the washing water is separated from the It is obtained by conveying together with a wet extraction device. As a result of pulverizing the main classification, contaminants contained in the larger particles of the combustion residue can be washed off in a subsequent cleaning step and thus separated from the renewable main classification. In this way, a high percentage of residue can be recycled as a reusable round, despite the fact that many contaminants are contained in these residues, without having to expect a large amount of cleaning from later contaminants.

Also in the second method described above, combustion control included in the first technical feature of the present invention is executed prior to the mechanical processing.

According to a very preferred embodiment of the combustion control system according to the method of the invention, the oxygen of the heating air from below is preferably 25 to 40% by volume, depending on the characteristics of the waste to be combusted (the characteristics of the waste). Preferably from 25 to 30% by volume. Further, according to a more preferred embodiment, the air for heating from below is preheated to about 100 to 400 ° C. These means may be used alone or together depending on the situation. The temperature of the fuel bed (typically the waste bed), which is a function of the fuel properties, is preferably set at 1000-1400 ° C.

All combustion control means for achieving the desired conditions in which fuel residues are converted into sintered and / or molten main circuits are such that there is a certain proportion of the complete sintering cycle (e.g. 25 to 75% by weight of the total amount of combustion residues). Is selected. According to this method, this means does not adversely affect the mechanical part of the grate because there is sufficient non-melting material to surround the molten ash on the fuel layer in the main combustion zone.

According to a further preferred embodiment of the invention, the fly ash is returned to the combustion process. This fly ash leaves the fuel bed with the combustion gases and is introduced via the boiler to the downstream flue gas filter.

A second feature of the third group of inventions, namely the mechanical treatment of the combustion residue comprising two methods, is carried out as described below.

According to the first embodiment according to the invention of the third group, the ultra-fines and micro-classifieds generated during the mechanical separation process are transferred to the combustion process. These classifications are subject to the combustion process once more, allowing their melting and sintering.

By this means, the disadvantages of the prior art treatments described earlier (even if they contain small amounts of all combustion residues, such as residues of undesirable properties to be avoided) are avoided. In addition, in comparison with the second-described prior art method, disadvantages regarding the generation of dust and the sealing of the furnace (air curl) can be avoided. Moreover, by conveying ultrafines and fines having undesired properties, the conveyed microparticle fraction is provided with an opportunity to agglomerate into combustion residues having desirable properties after being conveyed first or repeatedly. In addition, the proportion of recoverable combustion residues is further increased. The prior art method described secondly does not have this advantage because there is no process to return to the combustion process.

According to another embodiment of the third group of invention, the main classifier pre-purified with water in the wet extraction apparatus is rinsed with fresh water, and the water of the extraction apparatus carrying a relatively large amount of contaminants is removed so that the combustion residue and / or sintered Further improve the characteristics of the meeting. Because fresh water is used to rinse coarse fractions, the water used to rinse has a relatively small proportion of contaminants that contain it, which has the advantage of being able to be transferred to the flue gas scrubbing system without precleaning at least a portion of the water. . Moreover, this embodiment provides the advantage of supplying at least a portion of the water used to rinse to the wet brewing device. The water level in the drawing device can be maintained in this way. Since water continues to be carried along with discharged combustion residues, the water level in the discharge device drops. The water level needs to be kept high in any case. Since the water used to rinse contains negligible amounts of calcium and sulfur, there is no risk of clogged pipes and nozzles.

In the second method of mechanical treatment according to the present invention, even after the first separation step, even if the main classification contains a large amount of oversize classification (usually containing a large amount of waste metal), the other The coarse classification is further separated in the mechanical separation step according to the embodiment. The metal is separated by a magnetic separator.

In the embodiment of the group 3 invention, for example, the particle size of the ultra-micro classifier is less than 2mm, the particle size of the microclassifier is 2 mm or more, the range is less than 8 mm, the particle size of the coarse classifier is 8 mm or more, less than 32 mm The range, and the particle size of the oversize classifier, fall into a range of 32 mm or more. These values are provided to serve as a guide for a better understanding of the present invention. Clearly, each classifier contains some negligible minor subclassifiers. The microclassified material having a particle size of 2 mm or more and less than 8 mm coming out directly from the drawing device is a part of the combustion residue which is preferably conveyed to the combustion process. On the other hand, the particle size of the fine particle portion included in the particle size distribution of the circumference obtained as a result of the pulverization treatment according to the second method is comparable to the particle size of the microclassified substance supplied directly from the retrieval apparatus. Have Thus, the microparticle fraction of the pulverized round ash is regarded as a high quality microclassifier.

For example, in the second method, if the separation particle size is 32 mm in the first coarse separation step, that is, if the oversize classification is separated, for example, the second mechanical separation with the separation particle size set to 8 mm In the step, it is preferable to convey all the particle parts smaller than 8 mm to the combustion process.

It is advisable to separate the metal from the main classification to prevent damage to the mechanical separator by large pieces of waste metal.

From the main classification, which includes a coarse fraction of less than 32 mm, that is, large pieces of waste metal as well as other metal parts are released. Such metal parts can be used in a separate regeneration process.

Depending on the type of regeneration used for the combustion residues generated, it is convenient to separately remove the metals from the oversized and coarse classifications.

When combustion residues are used for road construction, it is better to, for example, remove the metal parts larger than 32 mm which are less suitable for this purpose and then further grind the oversized classification in the size reduction step.

In the second method, in order to obtain as large a classification as possible for regeneration, a thick classification separated from the main classification is produced by a step of reducing the size of the oversize classification, according to another embodiment of the invention of the third group. It is logical to mix with the pulverized combustion residue to form the first mixed fraction. In this case, since particles of an undesired particle size for regeneration, for example, particles having a particle size to be returned to the combustion process, are generated during the size reduction step, the first mixed classification is mechanically separated, which is preferable. It is advisable to remove particles with unspecified particle size.

If combustion residues are used for certain applications in road construction, this material should be compressible. This property is practically impossible without microclassification (eg, having a particle size of greater than or equal to 2 mm and less than 8 mm, as described above). For this reason, it is good to grind some of the coarse fraction in the size reduction step in order to intentionally ensure the presence of the required microclassifier. Therefore, it is preferable that such a microclassified particle size is contained in this ratio. Preferably, about 30% by weight of the coarse fraction is subjected to a size reduction step. The obtained microclassified substance and the ultramicroclassified substance are mixed with the coarse classification substance, and a 2nd mixed classification substance is formed. It is preferable that 70% by weight of the mixed classification intended for road use consists of coarse classification.

In this second mixed classification, the particle size occupying the majority is larger than 8 mm, and experience shows that these components have the necessary properties for regeneration. However, a small proportion of particles having a particle size of 2 mm or more and less than 8 mm is also required to ensure the above-mentioned compressive formation of the roadwork residue.

According to another embodiment of the present invention of the third group, the second mixed classification is washed with water from the wet extraction device to separate the first mixed classification. In this case, it is possible to reliably separate the part of particles smaller than 2 mm carrying particularly many contaminants from the renewable residue.

This washing water can preferably be transferred to a wet retractor as already described in other sentences. By returning water in this way, fresh water can be consumed as little as possible.

In order to wash away the combustion residue which adhered, it is good to wash | clean the separated metal using water from a extraction apparatus. Preferably, a screening step is used to mechanically separate the classification.

By adding a precipitant for soluble heavy metals to the water of the drawer, it can significantly help to increase the characteristics of the regenerated combustion residue. As a result, these heavy metals can be separated by adding a precipitant.

Embodiments of the invention according to the first to third groups will now be described further with reference to the accompanying drawings. In addition, specific values, such as the weight and% used below, are typical values for demonstrating embodiment, and should not interpret this invention limiting these values.

1 and 2 are two working system diagrams typically illustrating the method according to the invention of the first group. The invention of the first group will be described in more detail with reference to these figures.

In the method shown in Figs. 1 and 2, 1000 kg of waste (block 100 in the figure) having a ash content of 220 kg is supplied to the batch combustion system, so that 25 to 75% by weight of the combustion residue is completely sintered. It is burned in a transformed manner (block 102). A total of 300 kg of combustion residue is obtained. These residues fall into the wet extraction apparatus (block 104), are quenched there and then discharged (block 106). Through a separation process (block 108) comprising a screening step and a possible washing step, 200 kg of the complete sintered circumference is separated (block 110) and regenerated (block 112). 100 kg of combustion residues (block 114) not yet sintered are returned to the combustion process. The weight of fly ash leaving with the flue gas is 20 kg, which is recovered in the flue gas filter (block 116) and recovered by cleaning the boiler tube (block 118). The recovered fly ash is transferred to a separate disposal path (block 120).

In the method shown in FIG. 2, 310 kg of combustion residue is transferred to a wet recirculation apparatus, and 10 kg of fly ash is returned to the combustion process. The other method shown in FIG. 2 is the same as the method shown in FIG. Therefore, the same reference numerals are given to the same block as in FIG.

Next, an embodiment of the method according to the invention of the second group will be described with reference to the working system diagram of FIGS. 3 to 6.

As shown in FIG. 3, 1000 kg of waste (block 300) having a ash content of 220 kg is fed to the grate system (block 302) and then combusted. This combustion process produces 800 kg of flue gas (block 301) and 300 kg of combustion residues. This residue is fed to a wet reclamation apparatus (block 304) to remove 315 kg of combustion residue or circumference (block 306) by humidification. The removed residue is mechanically separated, in this case sorting, with a particle size of 8 mm (block 308). This process consists of a mains classifier (block 310) with a particle size greater than 8 mm (block 310) of combustion residues or circumferences of 215 kg, and a fines and ultrafines classifier (block 312) of about 100 kg with a particle size less than 8 mm. ). A humidification treatment (block 314) is carried out on the circumference having a particle size larger than 8 mm consisting of coarse and oversized classifications. In this step, 1000 liters of water taken out of the wet extraction apparatus is added to wash the circumference, and 15 kg of the microconstituents having a particle size of less than 8 mm are washed out. In practice, the circumference is cleaned on a sieve that passes a fraction of 8 mm or less. The water used to clean the circumference is returned to the wet brewing device together with the micro and ultra minute fractions. The cleaned circumference is taken out for use in a regeneration process such as, for example, road work (block 316). In addition, about 100 kg of the fines removed by sorting are usually returned to the grate system for further sintering purposes. However, the microclassifier can also be used for other processes (block 318). Since the combustion residue usually accompanies water when it is taken out of the wet brew, 40 liters of supplement or fresh water is added to compensate for the loss of water in the wet brew.

The above-described process may be changed as shown in FIG. In this modified example, subsequent to the humidification treatment of the main classification having a particle size larger than 8 mm, it is rinsed with fresh water. Specifically, 80 liters of fresh water (block 320) is added to a 200 kg main fraction to remove components incorporated by humidification using water from a wet brewing device (block 322). 40 liters of this rinsing water is used for cleaning or other waste treatment of the flue gas and the other 40 liters are returned to the wet brewing device as a supplement to compensate for the loss of water. The circumference cleaned in this way can be introduced into another regeneration process.

5 shows another embodiment of a process according to the invention of the second group. In this variant, 1000 kg of waste (block 500) having an ash content of 220 kg is fed to the grate system (block 502). This combustion process produces 800 kg of flue gas (block 504) and 320 kg of combustion residues. This combustion residue is fed to a wet reclamation apparatus (block 506). 336 kg of combustion residues are taken out of the wet retractor. This increase in weight is caused by the microparticles from the circumference, that is, the microparticles contained in the circulating washing water conveyed to the wet extraction device. 40 liters of water is added to the wet drawer to compensate for the loss of water. 336 kg of fly ash or combustion residue are fed to a filter which passes a fraction having a particle size of 32 mm (block 508). Oversize classifications having a particle size greater than 32 mm are initially transferred to a metal separator (block 510). The circumferentially separated circumference is transferred to a mill (block 512) which produces a circumference with a particle size of about 8 mm. The pulverized circumference is transferred to another filter (block 514) through which a fraction having a particle size of 8 mm is passed. 100 kg of fly ash or combustion residue having a particle size of less than 8 mm is removed by this mechanical separation process and is preferably returned to the grate system. This round is fed to waste or other processing (block 515). The remaining coarser residue is transferred to a metal separator (block 516). The metal component removed by the metal separator and the metal component separated by the metal separation step described above are collected and humidified. By this humidification, the particles of circumference adhering to the metal component are washed (block 518). As a result, 20 kg of ferrous and nonferrous metals are used for the regeneration process (block 520). Weighing or coarse classification (particle size: 8-32 mm) without metal (block 522) weighs 215 kg. A 60 kg coarse fraction is fed to the grinder (block 524) to produce a particle size greater than 2 mm. After milling, the milled classifier is mixed with 155 kg of a milled coarse classifier and the mixture is humidified using a filter that passes a classifier having a particle size of 2 mm (block 526). The 1000 liters of washing water required for the humidification is fed from the wet drawer. This humidification process yields 155 kg of circumference with a particle size of 8 to 32 mm and 45 kg of fine fraction having a particle size of 2 to 8 mm. These two classifications are used in the regeneration process, ie, civil engineering or roadside strata (block 528). On the other hand, the microclassified substance which has a particle size of less than 2 mm removed by the humidification process is conveyed by a wet extraction apparatus.

The working flow diagram of FIG. 6 shows a basic variant of the embodiment shown in FIG. 3, using a precipitant for soluble heavy metals. This precipitant is injected into the wet brew to reduce the concentration of lead in the water of the wet brew to 0.05 mg / L from the normal level of 2 mg / L (block 326). This precipitant reduces the amount of lead dissolved in about 20 liters of spin water, which humidifies 200 kg of spin, to 1 mg. 400 g of lead is incorporated into the flue gas generated by the combustion treatment (block 302). In a mechanical separation process (block 308) using a sieve which passes a sieve having a particle size of 8 mm (block 308), 200 kg of lead (block 310) in which 400 g of lead and 200 g of lead are transferred to a cleaning and regeneration process Remains on. On the other hand, 200 g of lead is conveyed to the grate system (block 302) together with the microclassified material (block 312) having a particle size of less than 8 mm.

In addition, embodiments of the method according to the third group of the invention will be described in more detail with reference to FIGS. 7 to 10.

As shown in Fig. 7, 1000 kg of waste (block 700) having a ash content of 220 kg is fed to the grate system (block 702) so that 25 to 75% by weight of the combustion residue generated is converted into a complete sinter main circuit. Burn out. This combustion results in 800 kg of flue gas (block 704) and 300 kg of combustion residues. This residue is fed to a wet reclamation apparatus (block 706), from which 315 kg of combustion residue or circumference is taken out by humidification (block 708). This extracted residue is sorted by mechanical separation, in this case a particle size of 8 mm (block 710). By this process, 215 kg of combustion residues or circumferences are divided into main fractions (block 712) having a particle size larger than 8 mm, and fine powders and ultra-fine fractions having a particle size of less than 8 mm (blocks 712). 714). The circumference with a particle size greater than 8 mm consisting of coarse and oversized classification is humidified (block 716). By this process, 1000 liters of water taken out of the wet extraction apparatus is added to wash the circumference, and 15 kg of the microcomponent having a particle size of less than 8 mm are washed out. In practice, the circumference is cleaned with a filter that passes a fraction having a particle size of 8 mm or less. The water used to clean the circumference is returned to the wet extraction apparatus together with the fine fraction and the ultrafine fraction. The cleaned circumference is taken out for use in a regeneration process such as, for example, road work (block 718). About 100 kg of the fines removed by the sorting are usually returned to the grate system for further sintering purposes. However, this microclassifier can also be used for other processes (block 720). Since combustion residues usually carry water together when they are taken out of the wet brew, 40 liters of make-up or fresh water is added to compensate for the loss of water in the wet brew.

The above process can be modified as shown in FIG. In this modified embodiment, following the humidification of the main classification having a particle size larger than 8 mm, rinsing with fresh water (block 722) (block 724). Specifically, 80 liters of fresh water is added to 200 kg of main classification to remove the components incorporated due to the humidification process using water from the wet brewing device. 40 liters of rinsing water is used to clean the flue gas (block 726) or other waste treatment, and another 40 liters of water is returned to the wet brewing unit as make-up water to compensate for the loss of water. The circumference cleaned in this way can be introduced into another regeneration process.

9 shows another embodiment of a process according to the invention of the third group. In this embodiment, 1000 kg of waste (block 900) with an ash content of 220 kg is fed to the grate system (block 902). This combustion process produces 800 kg of flue gas (block 904) and 320 kg of combustion residues. This combustion residue is fed to a wet reclamation apparatus (block 906). 336 kg of combustion residues are taken out of the wet drawer. This increase in weight is due to the fine particles contained in the circulating washing water returned to the wet extraction device. 40 liters of water are added to the wet drawer to compensate for the loss of water. 336 kg of fly ash or combustion residue is fed to a filter (block 908) that penetrates a fraction having a particle size of 32 mm. Oversize classifications having a particle size greater than 32 mm are initially transferred to a metal separator (block 910). The circumferentially separated circumference is transferred to a mill (block 912) which produces a circumference having a particle size of about 8 mm. The pulverized circumference is transferred to another filter (block 914) that penetrates a classification having a particle size of 8 mm. 100 kg of fly ash or combustion residues having a particle size of less than 8 mm are removed by mechanical separation and are preferably returned to the grate system. Dispose of the meal or other treatment (block 915). The remaining coarser residue is transferred to a metal separator (block 916). The metal component removed by the metal separator and the metal component separated by the metal separation step described above are collected and humidified (block 918). By this humidification process, the particle | grains of the circumference which adhere to a metal component are wash | cleaned. As a result, 20 kg of ferrous and nonferrous metals are used for the regeneration process (block 920). Weighing or coarse classification (particle size: 8-32 mm) without metal (block 922) weighs 215 kg. A 60 kg coarse fraction is fed to the grinder (block 924) to reduce to a particle size greater than 2 mm. After milling, the milled classifier is mixed with the finely milled 155 kg coarse classifier and the mixture is humidified using a filter penetrating the classifier having a particle size of 2 mm (block 926). The 1000 liters of wash water required for the humidification is supplied from a wet brewing device. This humidification produces 155 kg of circumference with a particle size of 8 to 32 mm and a fine fraction of 45 kg with a particle size of 2 to 8 mm. These two classifications are used in the regeneration process (block 928). On the other hand, the microclassified substance which has a particle size of less than 2 mm removed by the humidification process is conveyed to a wet extraction apparatus.

The working flow diagram of FIG. 10 shows a basic variant of the embodiment shown in FIG. 7 in which a precipitant for soluble heavy metal is used. This precipitant is injected into the wet extractor to reduce the concentration of lead in the water in the extractor from 0.05 mg / L to 2 mg / L, which is a normal level (block 728). This precipitant reduces to 1 mg of lead molten in about 20 liters of swirl water, humidifying 200 kg of swirl. 400 g of lead is mixed in the flue gas (block 702) generated by the combustion treatment (block 702). In a mechanical separation process (block 710) using a sieve penetrating a classifier having a particle size of 8 mm, 200 g of lead (block 712) in 400 g of lead and 200 g of lead sent to the regeneration process after washing. Remaining. On the other hand, 200 g of lead is returned to the grate system (block 706) together with the fines having a particle size of less than 8 mm.

As described above, according to the invention of the first group of the present invention, there is provided a method in which a complete sintering turn having required characteristics can be obtained without using a downstream melting or vitrification unit.

In addition, according to the invention of the second group of the present invention, a method capable of separating good circumferential classification products, a method capable of avoiding the problems caused by the presence of air from the furnace and the disadvantages of dust generation, and further, the consumption of water A method is provided for reducing this.

In addition, according to the invention of the third group of the present invention, a complete sintered turn having required characteristics can be obtained without using a downstream melting or vitrification unit, and a problem due to the intervening air from the furnace with a minimum of equipment. There is provided a way to control the combustion process so as to avoid and further reduce the consumption of water.

Although the present invention has been described with reference to the embodiments, it is not limited thereto. All modifications, changes, and additions that can be readily made by those skilled in the art are within the scope of the present invention.

1 is a working flow diagram illustrating an embodiment of a method according to the invention of the first group.

2 is a working flow diagram illustrating another embodiment of the method according to the invention of the first group.

3 is a working flow diagram illustrating an embodiment of a method according to the invention of the second group.

4 is a working flow diagram illustrating another embodiment of the method according to the invention of the second group.

5 is a working flow diagram illustrating another embodiment of the method according to the invention of the second group.

6 is a working flow diagram illustrating another embodiment of the method according to the invention of the second group.

7 is a working flow diagram illustrating an embodiment of a method according to the invention of the third group.

8 is a working flow diagram illustrating another embodiment of the method according to the invention of the third group.

9 is a working flow diagram illustrating another embodiment of the method according to the invention of the third group.

10 is a working flow diagram illustrating yet another embodiment of the method according to the invention of the third group.

Claims (5)

A method for improving the characteristics of the combustion residues produced by a combustion plant in which fuel is combusted on a combustion grate, thereby raising the temperature of the combustion residues generated under appropriate combustion control. The combustion residue is sintered, melted, or sintered and melted in advance on the fuel bed of the main combustion zone, and the molten or unsintered residue is extruded to the outside at the end of the combustion process, and then separated in a screening step of the main assembly. And operating a combustion control system to return it back to the combustion process. In the method for treating a residue produced by a combustion plant in which fuel is combusted on a combustion grate, the resulting residue is quenched with a wet extraction apparatus, and then the residue is transferred outward from the wet extraction apparatus. The wet combustion residue taken out from the wet discharge device is first separated into two classifications by a mechanical separation step according to the particle size using a sieve , The main classification consisting essentially of the coarse and oversized classifications is washed with water extracted from the wet retrieval device to separate the fine particles attached to the combustion residues, and A method for treating residue produced by a combustion plant, characterized in that for conveying the washing water together with the microparticle part removed during the washing step to the wet recirculation apparatus. In the method for treating a residue produced by a combustion plant in which fuel is combusted on a combustion grate, the resulting residue is quenched with a wet extraction apparatus, and then the residue is transferred outward from the wet extraction apparatus. The wet combustion residue taken out from the wet discharge device is first separated into two classifications by a mechanical separation step according to the particle size using a sieve , After the main fraction consisting of coarse and oversized fractions, which are essentially coarsely classified, is washed with water extracted from the wet extraction device, the fine particles attached to the combustion residue are separated, and A method for treating residue produced by a combustion plant, characterized in that for conveying the washing water together with the microparticle part removed during the washing step to the wet recirculation apparatus. In a method for treating residue produced by a combustion plant, in which a fuel is combusted on a combustion grate to raise a temperature of a combustion residue generated under appropriate combustion control. Operate the combustion control system to pre-sinter, melt or sinter and melt the combustion residue on the fuel bed of the main combustion zone, After the entire residue is quenched in the wet extraction apparatus, it is taken out from the wet extraction apparatus, The wet combustion residue taken out from the wet discharge device is first separated into two classifications by a mechanical separation step according to the particle size using a sieve, and then the main classification consisting of coarse and oversized classifications. Washing with water extracted from the wet extraction device to separate the fine particles attached to the combustion residue, and A method for treating residue produced by a combustion plant, characterized in that for conveying the washing water together with the microparticle part separated during the washing step to the wet recirculation apparatus. In a method for treating residue produced by a combustion plant, in which a fuel is combusted on a combustion grate to raise a temperature of a combustion residue generated under appropriate combustion control. Operating the combustion control system to pre-sinter or melt the combustion residue on the fuel bed of the main combustion zone, After the entire residue is quenched in the wet extraction apparatus, it is taken out from the wet extraction apparatus, The wet combustion residue taken out from the wet discharge device is first separated into two classifications by a mechanical separation step according to the particle size using a sieve, and then the main classification consisting of coarse and oversized classifications is essentially sized. Washing with water extracted from the wet extraction apparatus, which is subjected to a reduction step, to separate a portion of the microparticles attached to the combustion residue, and A method for treating residues produced by a combustion plant, characterized in that for conveying the washing water together with the microparticulates separated during the washing step to the wet extraction device.