FIELD OF INVENTION

[0001] The invention relates to a plant for processing solid municipal waste, and it will find application in industrial systems for processing organic, household and biodegradable waste to obtain organo-calcium soil conditioners (a. k. a. improvers) of alkaline nature based on the organic material contained in the waste.

BACKGROUND OF THE INVENTION

[0002] A method for processing solid household waste is widely known, and it includes sorting and processing of organic waste into compost, done by sequentially conducting in time a preparatory stage, homogenization, dehydration - followed by separation of waste by type. As a rule of thumb, household waste is most often contained in plastic bags, as they are strong, durable and difficult to tear. Therefore it takes a long time for the operators to open or tear the bags and release the waste to be treated and then, if necessary, to sort their contents before further processing.

[0003] Patent publication WO 2015187096 [1] is known: it describes a method and a device for anaerobic digestion of biodegradable substances, such as municipal waste, biological and/br organic waste. Anaerobic digestion is mainly used for the treatment of biodegradable material or materials, such as organic matter, bio-waste, biomass, household bio-waste, food waste and/or the like, resulting in the production of biogas. Anaerobic digestion takes place in devices in the presence of anaerobic bacteria, heat and in an oxygen-free environment. Anaerobic digestion takes place in stages where anaerobic bacteria break down biodegradable materials from one form to another and finally biogas is produced. The said patent publication describes a device, a bioreactor in its essence, and comprises three separate sections or chambers of cylindrical shape arranged consecutively in a vertical structure. A feed opening is located above the uppermost first section, where the material to be processed is fed through, and openings are provided laterally to the second and third sections - control samples of the processed material are taken through these openings. For the purpose of mixing the processed material, two rows are arranged in each section: one row of stirring blades below the other, fixedly connected to a centrally located in the sections shaft driven by a motor connected to it.

[0004] Publication EP 2205346 [2] (VALOROM) is known; it describes a Waste feeder consisting of a chute with an auger located therein; waste bags are fed through it to a waste treatment device consisting of a horizontal oriented rotating drum; metal combs are located inside it - they tear the bags and shred the waste, feeding (forwarding) it for further processing. The preparatory step includes mixing the municipal solid waste with a reagent, preferably quicklime: a chemical reaction takes place in it, as a result of which the temperature of the municipal solid waste is raised.

[0005] Patent publication EP 1747181 [3] (VALOROM) is known; it describes a waste treatment method, where as a result of carrying out the described preparatory operations carried out in a mixing device in which waste, quicklime and water are fed, the temperature of the municipal solid waste increases, hence the evaporation of the excess water begins - in some cases, it can be around and over 50% of the weight of the incoming stream of waste for processing. The dehydration process continues until a moisture content of up to 10-15% is reached. After the processing of the obtained mixture, the fractions are divided into types - organocalcium improver, reusable [recoverable] secondary raw materials for subsequent separation and ingredient for energy use, respectively.

[0006] The described method is carried out in series-like arranged and connected devices, the first of which is a drum-type mixer, consisting of a horizontally oriented rotating housing lying on support rollers located on two drive shafts connected to an absorber by a conveyor belt; in turn, the absorber is connected - by another conveyor belt - to a device for separating the material by size. As such a device, a rotating screen (sieve) is used — it separates the waste by size with the possibility of subsequent separation for their secondary use.

[0007] The described technological chain of interconnected devices and machines has a low degree of efficiency of mixing household solid waste with quicklime and water, expressed in the "sticking" of waste and the reagent in significant in size and weight tufas (tufts), mainly due to the low speed of rotation of the mixing drum.

[0008] There is insufficient efficiency of waste treatment, in particular the process of mixing waste and quicklime, as well as the subsequent drying of the material in the absorber, mainly due to the thick layer of waste in it, and efficient moisture separation is hindered thereof.

[0009] The described technological chain of machines and devices also has purely technical shortcomings, such as significant in size and weight facilities, significant in length lanes designed to transport treated waste between facilities, which generally increases the technological processing time per unit volume of processed material, as well as a significant area facilities occupy in the described location. In addition, a disadvantage is the large amount of electricity installed and consumed by the facilities, as well as the release of dust, moisture and other hazardous chemicals during the process, which to one degree or another makes it relatively inefficient and polluting the environment.

SUMMARY OF THE INVENTION

[0010] The purpose of the invention is to provide an installation for processing of solid household and biodegradable waste, thus allowing efficient carrying out of technological operations at increased production capacity, while providing efficient and controlled conditions for conducting exothermic reaction during mixing of solid and biodegradable household waste with a reagent (quicklime), where the joint arrangement of technological modules and working elements installed in them provides opportunities for construction of installations with different capacity, significant reduction of overall dimensions and weight of the installation as a whole, low energy costs, and it allows easy maintenance and operation.

[0011] The task is solved by a municipal solid waste treatment plant - the latter comprises a waste feeding device consisting of a chute with an auger located therein, waste bags are fed through to a waste treatment device. It is characterized by the fact the chute, with an auger located in it, contains at least two independently rotating spiral augers installed in it in opposite directions, which tear the bags and break up the waste, feeding them for further processing to the hopper housing, whereby a vertically oriented auger is installed in the. hopper, thus ensuring the internal exchange/circulation of the already mixed input material with the reagent.

[0012] The chute is located at an angle of more than 15 degrees to the horizontal, and the shafts of the auger spirals mounted in the chute are connected to a separate drive system for each of them or a joint one. Externally to the metal body of the chute technical means are mounted - for feeding the processed material and the reagent, as well as technical means for conducting and controlling the technological process.

[0013] At the end of the chute body there is an outlet, discharged/connected to the hopper housing - in the shape of a truncated pyramid. A vertically oriented auger is placed inside the hopper, thus ensuring the internal exchange/circulation of the already mixed input material with the reagent. The air-tight sealed housing of the hopper together with the vertical auger perform the function of an absorber removing moisture from the incoming material by convection with a pipe system and a drying installation for air mixtures containing moisture, with at least one opening - laterally, in the conical part of the hopper lid - for supplying the air returned by the system, while the highest part of the hopper lid is provided with a suction opening for the exhaust air containing water vapor, thus creating under-pressure [negative pressure] in the hopper, preventing emissions of water vapor. The support element of the hopper is made in the shape of an inverted truncated pyramid or cone, oriented with its narrow base to the bottom and it comprises the drive shaft of the vertical auger. The bottom of the hopper is provided with at least one device for removing/discharging processed and homogenized solid household waste, and waste is screened (sieved) by means of a vibrating screenAs.

[0014] According to a variant embodiment of the installation, the hopper housing is made in a cylindrical shape with a bottom in the shape of an inverted truncated cone. In this embodiment, the support element is also cylindrical in shape; in this case the vertical auger screw is also located inside the cylindrically shaped hopper.

[0015] An alternative embodiment of the vertical auger screw is to pair two counter-rotating helical spirals.

[0016] Another variant embodiment of the installation is having two or more vertical auger screws 6 mounted in the mixing hopper and they are displaced relative to each other vertically.

[0017] According to a variant embodiment of the installation, after the outlet of the chute another mixing chute with a double auger screw is mounted, identical to the main inlet mixer from the first chute; at the outlet of it a second hopper identical to the first one is mounted, and its outlet returns the mixing material back to the first hopper. This creates a system of two screw mixers and two hoppers, where the same material circulates continuously during processing in a closed system, increasing the efficiency of mixing, moisture separation and conversion of the incoming processed material into the desired form. The upper part of the hopper body is equipped with openings and mechanisms for feeding reagent and technologically necessary water, as well as a system for extracting compressed/pressured air. [0018] The described implementation of the installation (plant) allows the implementation of variant implementations, and depending on the type and composition of the processed materia! or the required production capacity, the device may contain only one module, but also variants in height or horizontally, one above/under the other or more modules may be placed, with or without vertical internal systems.

[0019] According to the utility model, the solid waste treatment plant is characterized by a compact design due to the simultaneous functions of mixing and absorption of the processed material, as well as the possibility of combining more than one consecutively connected modules. The proposed design allows efficient carrying out of operations for mixing the waste with the reagent (quicklime) and carrying out the necessary homogenization. The plant operates at low energy costs, as long as the stages of solid waste treatment are performed in adjacent modules, where the material is transported from one module to another through the mixing auger and by gravity.

[0020] Waste processing is also favored by the fact a screen (sieve) or a screen system is placed at the outlet of the mixing hopper 5, which allows the necessary separation of the residue obtained after processing (for example into several fractions separated by size). The vertical arrangement of the modules facilitates the movement of the material from one module to another, as well as the operation of the vibrating screens 8 located in the bottom of the hopper 5. The modular design of the installation allows for the construction of an indefinite number of devices working simultaneously with increased production capacity and at the same time occupying a much smaller area than the devices described in the known level of technology, including consecutively connected the following: a horizontal drum mixer, conveyor belts, an absorber and a screen.

[0021] Another advantage is having the individual modules of the installation and technological stages integrated in a single system of devices, so that the total space and volume occupied by the installation is significantly reduced. This, in turn, allows larger waste treatment systems to be designed and implemented, and located in plants or industrial areas with limited space.

With the proposed arrangement of the modules, several technical and technological advantages shall be achieved simultaneously, expressed in the possibility of building a compact system occupying a small area, where the system installations are mobile and easy to install, service/maintain and repair at low operating costs.

BRIEF DESCRIPTION OF THE DRAWING

[0022] Fig.1 A diagram of the installation for processing solid waste.

EXEMPLARY EMBODIMENT OF THE INVENTION [0023] Solid waste treatment plant comprising a chute 1 with an auger 1.1 of at least two independently rotating spiral augers 1.1 - the latter tear the bags and shred the waste by feeding it for further processing to the housing of the hopper 5, wherein a vertically oriented auger 6 is placed in the hopper 5; the auger ensures the internal exchange/circulation of the already mixed input material with the reagent.

[0024] The chute 1 is located at an angle of more than 15 ° to the horizontal, the shafts of the auger spirals 1.1 mounted in the chute 1 are connected to a separate drive system for each of them or to a joint one. Externally to the metal body of the chute 1 technical means are mounted for feeding the processed material 2 and the reagent 3, as well as technical means 4 for conducting and controlling the technological process.

[0025] At the end of the housing of the chute 1 there is an outlet 1.2., discharged/connected to the body of a hopper 5 in the shape of a truncated pyramid. A vertically oriented auger 6 is placed inside the hopper 5, thus ensuring the internal exchange/circulation of the already mixed input material with the reagent. The air-tight sealed housing of the hopper 5 together with the vertical auger 6 perform the function of an absorber removing moisture from the incoming material by convection with a pipe system and a drying installation for air mixtures containing moisture, with at least one opening 5.1. - laterally, in the conical part of the hopper 5 lid - for supplying the air returned by the system, while the highest part of the hopper 5 lid is provided with a suction opening 5.2. for the exhaust air containing water vapor, thus creating a underpressure [negative pressure] in the hopper 5, preventing emissions of water vapor. The support element of the hopper 5 is made in the shape of an inverted truncated pyramid or cone, oriented with its narrow base to the bottom and it comprises the drive shaft of the vertical auger 6. The bottom of the hopper 5 is provided with at least one device 7 for removing/discharging processed and homogenized solid household waste, and waste is screened (sieved) by means of a vibrating screen/-s 8.

[0026] According to a variant embodiment of the installation, the hopper 5 housing is made in a cylindrical shape with a bottom in the shape of an inverted truncated cone. In this embodiment, the support element is also cylindrical in shape; in this case, the vertical auger screw 6 is also located inside the cylindrically shaped hopper 5.

[0027] An alternative embodiment of the vertical auger screw 6 is to pair two counter-rotating helical spirals. Another variant embodiment of the installation is having two or more vertical auger screws 6 mounted in the mixing hopper 5 and they are displaced relative to each other vertically.

[0028] According to a variant embodiment of the installation, after the outlet 1.2. of the chute 1. another mixing chute 1 with a double auger screw 1.1. is mounted, identical to the main inlet mixer 1.1. from the chute 1; at the outlet of it a second hopper 5 identical to the first one is mounted, and its outlet returns the mixing material back to the first hopper. This creates a system of two screw mixers and two hoppers, where the same material circulates continuously during processing in a closed system, increasing the efficiency of mixing, moisture separation and conversion of the incoming processed material into the desired form. The upper part of the hopper 5 housing is equipped with openings 5.3. and mechanisms for feeding reagent and technologically necessary water, as well as a system for extracting compressed/pressured air.

[0029] The described implementation of the installation allows the implementation of variant implementations, and depending on the type and composition of the processed material or the required production capacity, the device may contain only one module, but also variants in height or horizontally, one above/under the other or more modules may be placed.

[0030] The municipal solid waste treatment plant works as follows: in the lower part of the housing of the chute 1, through the feed opening, solid household waste to be processed is fed, while a technologically determined quantity - by means 2 and 3 for water and reagent, corresponding to the quantity of the waste - is fed at the same time. The drive system is activated, where the drive shafts rotate the screw augers 1.1 located on them, rotating opposite to each other, whereby the supplied solid waste and reagent are stirred, mixed and homogenized thanks to the appropriately shaped and oriented under a specific angle operational screw spirals 1.1, which form a contact surface, ensuring efficient mixing of the volume of processed waste, the reagent and the supplied process water. It is recommended the mixing of the waste and the reagent lasts for at least a few minutes, and then the homogenized material is fed through the unloading outlet of the chute 1 into the hopper 5 to have the moisture contained in the mixture absorbed. The vertical augers 6 mounted in the hopper 5 create simultaneous rotational, translational, helical and directed movement of the processed material, as the thus formed rotational helical flows of the mixed materials are mixed as efficiently and effectively as possible with the reagent. It is recommended the mixing and homogenization of the waste and the reagent in the hopper 5 through the screw 6 mounted vertically inside it lasts for at least 20 minutes, and then the mixed material is fed by a gravity manner to an adjacent second module of the same installation, where the material is again stirred in the chute 1 for at least 20 minutes; during this time the thermochemical reaction with the reagent continues, as well as dehydration of the treated material, which is then fed through the discharge outlet 1.2 of the chute 1 to the hopper 5 of the second installation module, where the material is finally dewatered to a predefined humidity according to the operator’s requirements.

[0031] The invention is not limited to the embodiments described above; the latter should be considered illustrative only for the purposes of applying the principles of the utility model where the installations of the system are mobile and easy to install, service/maintain and repair at low operating costs.