CS566290A3 - Process for utilization of solid refuse, particularly domestic refuse and apparatus for making the same - Google Patents

Description

-V - 1 - yjDr. SfíHoš ET ŠET £ ČKAadvokát 11504 PRAHA 1, Žitná 25 • o a> o

XJ> o o <oCO XK «_ z J> m> o <r ~ - to> Γ3 ►— · ΤΓ ·

A method of recovering solid waste, including household waste, and a facility for performing this waste.

Technical field

BACKGROUND OF THE INVENTION The present invention relates to a process for the recovery of solid wastes which contain at least 30% by weight of cellulase.

Said method is preferably used for the evaluation of household garbage. In general, however, the method of the invention may be used to evaluate all types of garbage, whether it be household garbage, industrial wastes, agricultural wastes or other garbage, which, however, must contain the aforementioned minimum amount of cellulose-based substances.

The invention also relates to an apparatus for carrying out the above-defined method for the recovery of solid waste, in particular household waste containing at least 30% by weight of cellulosic material.

It is known that the storage of such garbage by landfills has a detrimental effect on the environment and that these landfills are a negative environmental factor. The method according to the invention eliminates the necessity of establishing said ecologically harmful landfills, because it processes the waste into an inert material which is no longer environmentally harmful and which in turn can be a useful product. In particular, the inert material thus obtained, which has a character of fine or medium grain size, can be used in the construction industry, for the sanding of roads and roads, and for the construction of embankments and dikes. This material is biologically unobjectionable, as there is no bacterial growth during - 2 - time period.

BACKGROUND OF THE INVENTION Currently, two major types of handling of these garbage are known. These garbage can, as already mentioned, be stored in such a manner. safe landfills or wild landfills located somewhere in the countryside. Neither of these ways of waste processing allows for the utilization of these wastes for a useful product. And both of these methods are the source of environmental polution. In the pyrolysis of this type of garbage, which mainly contains chlorinated or fluorinated plastics, toxic gases such as chlorine and dioxyn are formed. In the case of long-term storage of such garbage, during the course of time biogas (in particular methane) is formed which is dangerous due to the possibility of their ignition and / or unpleasant due to their odor.

In addition, the mineralization of these rubbish in the earth leads to the formation of dangerous earth cavities, which threaten to break through. SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a process for treating solid wastes, in particular household garbage, containing at least 30% by weight of cellulosic material which is not accompanied by environmental pollution and to which the garbage is processed. useful product, usable in some industry activity.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for evaluating solid wastes, in particular household garbage, containing at least 30% by weight of cellulosic material, comprising pre-crushing and sorting said wastes in order to remove metal particles. the mixture of homogeneous mass comprising said shredded refuse and mineral products is thermally treated in a tubular reactor equipped with a conveying screw and heated by introducing hot flue gases, said reactor being kept under low pressure and said mixture comprising lime, carbonate calcium and caustic soda, wherein the heat treatment and the presence of said mineral products provide in the first portion of the reactor an increase in the temperature of the mixture up to the inactivation temperature. l-n-ho-zá-r-n-í -.-

The process according to the invention is advantageously characterized in that said homogeneous mass comprises said waste garbage containing 20 to 40% moisture and 30 to 40% natural calcium carbonate, based on the weight of said homogeneous mass.

The process of the invention is preferably characterized in that the mixture additionally contains carbonate silicates.

The process according to the invention is advantageously characterized in that the content of mineral products other than calcium carbonate, which has been pre-intimately mixed with the litter, is 5 to 35% by weight, based on the weight of said homogeneous mass.

The process according to the invention is advantageously characterized in that the mixture introduced into the reactor also contains neutralizing substances selected from the group comprising calcium carbonate, precipitated calcium carbonate, powdered barite, carbonate silicates, powdered earth, sacharoid gypsum in powder, bauxite powder and mixtures thereof, to control the density of products leaving the reactor.

The process according to the invention is advantageously characterized in that the mass leaving the reactor after the separation and the optional addition of neutral weighting agents is treated with at least one agglomeration binder in order to obtain the sand product of the granulometry. It is also an object of the present invention to provide a device for carrying out the aforementioned method, comprising: a tubular reactor equipped with a conveying screw; a combustion chamber opening into the inlet of said tubular reactor for direct supply of heat to the reactor; and means for maintaining a low vacuum in the reactor.

The device according to the invention is advantageously characterized in that it comprises a belt mixer arranged upstream of the tubular reactor to produce said homogeneous mixture of cracked refuse.

The device according to the invention is preferably characterized in that it comprises a separator arranged downstream of the tubular reactor and transferring the mass leaving the reactor to a very fine powder.

The device according to the invention is advantageously characterized in that it comprises a mixer disposed downstream of said separator and agglomerating said powder to particles and means for drying / crystallizing said obtained particles.

As mentioned above, said wastes are subjected to a specific heat treatment which induces a reaction accompanied by light radiation. !

The waste to be treated is pre-crushed by the metal particles which they contain. The rubbish thus disintegrated is then blended with the mineral products of the homogeneous mass. The waste is blasted in such a way that it is in the form of very fine particles from which the homogeneous mass is readily prepared.

Said wastes contain at least 30% by weight of cellulose-like substances. As mentioned above, these are preferably household garbage, which generally contain about 60% by weight of cellulosic materials, 3% by weight of plastics, 7% by weight products, glass by weight and 20% by weight of different materials.

The waste in the process according to the invention is thermally treated in admixture with mineral substances, especially lime, calcium carbonate and sodium hydroxide. Tytominerals are intended to exothermically during the course of the process. Preferably, these minerals are chosen so as to exert maximum activity in the treated mixture in reasonable coats in the mixture. With the advantage of using very reactive lime. In the case of calcium carbonate, it is preferable, for economic reasons, to use, in particular, calcium carbonates of natural origin which are optionally enriched with calcium, for example calcium chloride, if necessary. A mixture of homogeneous mass comprising scattered scrap and mineral products is directly heated at the inlet into the reactor by hot flue gas. These hot gases may, for example, come from the combustion of gas or oil.

The reactor which is used for this purpose is provided with a conveying screw (non-worm or non-worm). This conveyor screw allows the mass of the reactants inside the reactor to move, thus providing some mixing of this mass.

The reactor is kept under low vacuum to remove gas from the reactor. In fact, mainly water vapor is removed from the reactor.

It has been shown that in the reactor described above it is possible to fossilize waste containing at least 30% by weight of cellulosic substances without causing harmful environmental contaminants. This accelerated fossilization is likely to occur when intense light radiation occurs in the reactor. The aforementioned accelerated fossilization is the result of the heat shock effect of the heat shock because the hot flue gas is blown directly into the reactor inlet, into a mixture containing certain reactants.

The process of the present invention results in the aforementioned beneficial effect of inhibiting the formation of harmful substances and in the formation of an inert product (in the form of brittle debris) only when said light radiation in the form of an aureole is observed in the reactor.

In order to produce the aureole, Ψ is required. - 7 - to respect the parameters having the aureolytic effect; these parameters are both the composition of the mixture introduced into the reactor and the temperature to which the mixture must be heated at the reactor inlet.

Determination and optimization of these parameters by routine testing.

The homogeneous mass containing the shredded waste is preferably obtained by mixing said waste with calcium carbonate, preferably natural calcium carbonates, to which calcium chloride has been optionally added, prior to entering the reactor. This blend is well formed only when the rubbish contains some degree of moisture in the blend. damp-s ^ - but you. must not interfere with the subsequent reaction. The moisture content is preferably 20 to 40% by weight. In order to set this desired degree of humidity, the trash can / if necessary / be pre-dried / partially / or vice versa. Generally, 30 to 40% by weight of natural calcium carbonates are added to the codpads with said moisture level. As mentioned above, said calcium carbonates may be pre-enriched with calcium, for example, in the form of calcium chloride. Other mineral substances, especially calcined lime and caustic soda, are then added to the homogeneous mass of pulverized rubbish and calcium carbonates in order to obtain the desired heat quality. The carbonate silicates (Na2Ca2 / g4H2 SiO2 / CO2) type are also preferably added. The presence of these mineral products, i.e. lime lime, calcium carbonate (in particular natural calcium carbonates optionally enriched with calcium chloride) is also present. foamed sodium hydroxide, and preferably carbonate silicates, makes it possible to achieve the desired result, which is to form an "aureole" by direct heating of the mixture and to obtain an inert mass in the form of brittle crumbs. Calcium The above-mentioned mineral products, other than calcium carbonate (optionally containing calcium chloride), are intended to produce an effect of the invention (to form an "aureole") in an amount of about 5 to 35% by weight of said homogeneous mixture. . Their minimal amount obviously depends on the composition of the homogeneous mass and in particular on the content of the cellulose character in the waste being treated. 3 are preferably present in almost equivalent amounts (1/3, 1/3, 1/3): - lime in an amount of 10 to 45%, - caustic soda in an amount of 5 to 35%, - carbonate silicates in an amount of 10 to 45%, based on the weight of this ternary mixture (burnt lime + caustic soda + carbonate silicates).

The reactive mass thus obtained, formed by said homogeneous mass and said mineral products, undergoes a thermal shock at the inlet to the reactor by contact with the hot exhaust gases. . It has been observed that 250 to 300 C occur at the temperature of said reactive mass to produce the " aureole " according to the invention, which is necessary for the fossilization of refuse. C.

As already mentioned, the mass leaving the reactor is in the form of brittle, frangible pieces. Preferably, the pieces thus obtained are separated. Sand is obtained with a density of about 0.3 to 0.5. However, such sand is difficult.

EasaiisS &amp;amp;amp;amp; ns. &Apos; - 9 &apos;, therefore, are used in the process of the invention to provide a weighting agent to increase its density. These weighting agents can be added at least in two stages of the process of the invention. In particular, they can be added to the resulting sand during its transition into the reactor into the separator and / or added during the preparation of the homogeneous mass consisting of shredded waste and calcium carbonate prior to its introduction into the reactor.

If these loadings are added downstream of the reactor, any type of load can be used. If these weighting agents are added before the reactor. thereafter it is necessary to use non-tert-butanol in the form of tert-butanol. In this invention, the term " hydrophobic acid " is used herein to refer to heat-treating materials which are compatible with the thermal reaction / heating + &quot; aureola &quot;. Such neutral loaders may be selected from the group consisting of calcium carbonate, precipitated calcium carbonate, powdered barite, carbonate silicates, powdered clay, powdered sachoid gypsum, powdered bauxite, and mixtures thereof. It is to be understood, therefore, that calcium carbonate and carbonate silicates may be present in the process of the invention in higher amounts than those above; For illustrative purposes, it can be clarified that the calcium carbonate formed and the precipitated calcium carbonate may form up to 50% by weight of said homogeneous mass / calcium carbonate is still contained, on the one hand, as a reactive component and on the other hand as a neutral substance. .

Baryte (with its sediment) may contain 0 to 30% by weight; clay may be present in an amount of 0 to 15% by weight; gypsum may be present in an amount of 0 to 20% by weight; bauxite may be present in an amount of 0 to 20% by weight. The carbonate silicates may generally be present in an amount of up to 30% by weight, based on the total weight of the composition, of the reactor inlet.

The weighting agents mentioned allow to obtain a prescribed density. If it is desired to adjust the granulometrium product exiting the reactor, i.e. to increase this granulation, then the process according to the invention will include an additional stage.

The mass leaving the reactor has a very fine to non-palpable powder after separation and, if appropriate, addition of neutralizing substances.

Such a powder is preferably processed by agglomeration to increase its granulometry; the result of this agglomeration treatment is medium sand, which is useful in the construction industry.

The agglomeration binder is preferably mixed with the sand in a vertical Flexomix agglomerator. The mixture was then dried, causing the coupling to crystallize.

Said agglomeration binder must be chosen to respect the stable and inert nature of the product obtained by the process of the invention. This agglomeration insurance must not introduce bacteria into the resulting product. In particular, the silicon sodium may be used as the agglomeration binder to react with the calcium present in the grains of the product.

It is also possible to use a binder based on quicklime, cement slag, blast furnace slag and carboxy-methylcellulose '(or equivalent). Another useful agglomeration binder is a water-soluble pitch binder.

This type of powder material processing to increase its granulometry is a perfectly known and technically mastered processing.

The process according to the invention thus evaluates solid wastes of the above-mentioned type without the formation of harmful substances, and it is not necessary to heat the active mass in the reactor to a temperature in excess of 300 ° C / pyrolysis of the plastics. The flue gas fed to the reactor input for the purpose of: - - - - - - - - - - - - - - - - - - - They are found in the bulk composition, in particular in the form of the disclosed aureols.

As already mentioned, it is an object of the invention to provide a device for carrying out the above-described method according to the invention. The apparatus is essentially comprised of a tubular reactor equipped with a conveyor screw, a combustion chamber extending into the reactor inlet for supplying heat to said inlet, means for supplying materials to the reactor, and means for maintaining a weak vacuum in the reactor. '

A reactive mass is introduced into one end of the reactor, consisting of a homogeneous mass containing rbc droplets and optionally neutral loadings and various mineral products, by means of at least one vent. The reactor may also be equipped with one chamber passage for supplying a homogeneous mass and a second chamber passage for supplying mineral products. This co-vent or leak-proof culvert is hermetically sealable, so that when the materials are introduced into the reactor, the weak vacuum that is maintained in the reactor is not disturbed by the supplied air. v. The aforementioned masses are fed through the conveyor screw through the reactor. This conveyor screw also ensures constant homogenization of the mass inside the reactor. A combustion chamber is located in front of the reactor. It may be a fuel oil burner or a gas burner burner.

The hot flue gas produced in the combustion chamber then leads to the reactor inlet. As mentioned above, the desired effect is achieved, in particular when the temperature at the reactor inlet is about 50 ° C to 600 ° C.

The reactants are introduced into the reactor with a temperature corresponding to ambient temperature and are thus subjected to heat shock at the reactor input.

Preferably, the homogeneous mass containing the shredded waste, calcium carbonate and other mineral products is pre-introduced into the reactor in a belt mixer.

At the outlet of the reactor, some of the mass produced is cooled. The output of the produced mass from the reactor is preferably carried out through a decompression chamber which allows separation of both the gas and the solid.

Said solid produced is removed from the reactor by gravity. Preferably, the gaseous entrained fines are recovered such that the resulting gaseous phase is introduced into at least one cyclone. The gas phase obtained, which is mainly formed by steam, is discharged, for example, by the chimney.

As mentioned above, the resulting solid 13 product is in the form of brittle pieces. These pieces may be transferred to a powder in a separator which optionally also forms part of the apparatus of the invention and which is a reactor.

The powder thus obtained is then processed in a mixer / crystallizer to control its granularity. In said mixer, the powder is mixed with at least one agglomeration binder. Accordingly, the apparatus of the invention may advantageously consist of a reactor and its means for heating the reactor, introducing materials into the reactor, and means for maintaining a vacuum in the reactor, wherein a belt mixer is introduced upstream of the reactor and a separator and assembly are sequentially incorporated in the reactor. va mixer / dryer-crystallizer. 1 and 2 illustrate an embodiment of the process of the invention. Figure 1 shows a flow diagram of a waste processing apparatus according to the invention, while Figure 2 shows the base elements of the apparatus.

In these figures, the individual reference numerals denote: 1 hopper with a mobile bottom and a mobile hatch, 2 a screw shredder, 3 a defroster separator; 4 a belt conveyor with a magnetic drum; 5 conveying a screw shredder, 6 a magnetic cage / at this stage of the device, the rubbish is crushed and metal parts are contained which contain a screw shredder, a 8 conveyor conveying a belt mixer, 9 a powdered silo with a screw cap, including in particular natural carbonates lime, 14 10 belt mixer, 11 transporter fed reactor, 12 powder silo with worm closure, 13 ......... · reactor for accelerated fossilization, with pro. The means 11 and 12 form the means for feeding the materials into the reactor, 14 and 15 cyclones / for the recovery of fine solids /, 16 the transporter loading the separator, the 17 separator / vertical / 18 transporter loading the agglomerator, the 19 vertical agglomerator Flexomix, the 20 the carrier for drying a trough, 21 a drying trough, 22 a transporter feeding a storage pile of product, 23 a combustion chamber, 24 a conveying screw inside the reactor, 25 observation openings of the interior of the reactor, 26 a discharge trough of the reactor. 11,869.2 t / h of waste is treated in this plant. The passage time of the mass inside the reactor is about 30 microns. The luminous radiation forming the "aureol" can be observed in the first third of the reactor, while the temperature inside the reactor is 250 ° C. The inlet reactor temperature is 500 to 600 ° C.

Claims (10)

and·-. ..V .., '- <1 «?, κ e.ev ®w> V-v ATSNTOVE A method of recovering solid wastes, especially households, containing at least 30% w / w. garbage therein of a cellulosic nature, including pre-crushing and sorting said garbage to remove metal fractions, characterized in that the ... The non-standard operation of the reactor is equipped with a screw conveyor equipped with a conveyor screw and a heating element. by introducing the hot flue gas at its inlet, said reactor being kept under low vacuum and said mixture containing calcined lime, calcium carbonate and sodium hydroxide, wherein the heat treatment and the presence of said mineral products provide in the first portion of the reactor to increase the temperature of said mixture to creating intense light radiation. Process according to Claim 1, characterized in that said homogeneous mass comprises said split waste containing 20 to 40% moisture and 30 to 40% of natural calcium carbonate, based on the weight of said homogeneous mass. A process according to claim 1 or 2, characterized in that said mixture comprises more carbonate-silicates. - II - 4. A process as claimed in claim 1, wherein the content of mineral products other than calcium carbonate which has been pre-intimately mixed with the disintegrated waste is 5 to 35% by weight of the homogeneous mass. 5. Process according to claim 1, characterized in that the mixture introduced into the reactor also contains inert substances of an inert nature selected from the group consisting of calcium carbonate, precipitated calcium carbonate, barite powder, carbonate silicates, powdered clay, powdered sacharoid gypsum, bauxite powder. and mixtures thereof to control the density of the products leaving the reactor. 6. A process according to any one of claims 1 to 5, characterized in that the mass leaving the reactor after separation and optionally adding neutral weighting agents is treated with at least one agglomeration binder in order to obtain a sand product of said granulometry. Apparatus for carrying out the method according to any one of the preceding claims, characterized in that it comprises: - a tubular reactor (13) equipped with a conveyor (24), - a combustion chamber (23) leading to the inlet of said tubular reactor (13) with a straightforward supplying heat to the reactor; means (11,12) for feeding the materials to the reactor III - means for maintaining a low vacuum in the reactor. 8. Apparatus according to claim 7, characterized in that it comprises a belt mixer (10) arranged by a pre-tubular reactor (13) to prepare said homogeneous mixture of shredded refuse. 9. Apparatus according to claim 7 or 8, characterized in that it comprises a separator (17) arranged in the tubular reactor (13) and transferring the mass leaving the reactor to a very fine powder. Apparatus according to claim 9, characterized in that it comprises a mixer (19) positioned downstream of said hardener (17) and agglomerating said powder onto said seed, and means (21) for drying / crystallizing said obtained particles. Represents: