EP2548724A1

EP2548724A1 - Device for producing solid fuel in a form of shaped profiles and method for producing solid fuel

Info

Publication number: EP2548724A1
Application number: EP12005066A
Authority: EP
Inventors: Zbigniew Musial
Original assignee: Zaklady Urzadzen Kotlowych Staporkow Spolka Akcyjna
Current assignee: Zaklady Urzadzen Kotlowych Staporkow Spolka Akcyjna
Priority date: 2011-07-18
Filing date: 2012-07-09
Publication date: 2013-01-23
Also published as: PL395694A1

Abstract

The invention relates to an apparatus for production of solid fuel in the form of pre-formed blocks, comprising at least one container for raw materials, connected with a granulator directly or indirectly by means of a fine grinding section and/or a homogenisation section, characterised in that the flat granulator (10) comprises a flat matrix (12) provided with holes (16) and a movable kneading roller (13) which adjoins it and is provided with punches (17) on it perimeter. The invention also relates to method of producing solid fuel.

Description

The object of the invention is an apparatus for production of solid fuel in the form of pre-formed blocks and a method of solid fuel production.
Processes of treatment of fine-grained solid fuels, often waste ones, such as hard coal and/or lignite or coke which are left-overs of energy fuels featuring low usability are known. Processes of transforming solid fuels, e.g. by making briquettes, pellets or granulate also employ the use of biomass of various origin and possibly fillers and binders.
From the patent description PL035571 there is known a method of briquetting of the crumbled solid fuels by pressing a raw material blend, which has been previously heated up. In this method, raw materials are extruded in moulds and ready-made briquettes are shaken out.
From the patent description PL201369 , there is known a method of producing solid fuel by homogenising and briquetting the ingredients, the key process phase taking place in a circular kneader.
The known processes of granulating solid fuels consist in forcing the homogenised raw material through a perforated matrixes are based on raking up the raw material which is forced through proper holes of the matrix under its own weight load or by the raking blades or by other forces exerted on the raw material blend. However, the raw material compaction is relatively loose and slightly porous while the structure of produced briquettes or pellets may comprise microcavities filled with air or volatile substances emitted in the raw material treatment process.
The invention makes it possible to use various components in the process of moulding crumbled solid fuels. Components of various types are known a/o from the patent description PL 194 593 which revealed briquettes comprising coal dust and/or coke and/or sawdust and/or peat and/or straw, and in which collagen produced from natural animal skins was used as a binder. In the Polish patent descriptions PL174678 and PL 174972 , crumbled energy wastes were briquetted with the use of starch and its derivatives which were additionally modified with urea-formaldehydes. Magnesium and zinc oxides were used a mineral binder in the briquetting process revealed in the Polish patent description PL177076 .
The apparatus and the method according to the invention can be applied to any, e.g. aforementioned raw materials, mostly solid fuels based on coal, coke and biomass. The purpose of the invention is therefore to design an enhanced, universal apparatus to produce pre-formed solid fuels, especially a solid fuel granulator.
An apparatus for production of solid fuel in the form of pre-formed blocks, comprising at least one container for raw materials, connected with a granulator directly or indirectly by means of a fine grinding and/or homogenisation section, according to the invention comprises a flat granulator comprising a flat matrix provided with holes and a movable kneading roller, adjoining the matrix and provided with punches on its perimeter, the holes in the upper part of the matrix having a conical shape that changes over in the further part to a shape of cylinders. The length of the punches is equal to or smaller than the depth of the conical part of the holes and the diameter of the punches is smaller than the diameter of the conical part of the holes. The matrix is connected to a drive unit, which sets the matrix in reciprocating motion and possibly also the roller is connected by means of a shaft with a drive unit which sets it into a rotational motion.
The object of the invention is also the method of producing solid fuel in the form of pre-formed blocks, comprising the raw material delivery by means of at least one container and possibly fine grinding and homogenisation of the raw material, characterised in that the fuel blocks are pre-formed in a flat granulator comprising a flat matrix with holes which are situated on its upper surface and through which, by means of at least one kneading roller adjoining it and provided with punches on its perimeter, the raw material is forced through the matrix, wherein the raw material is charged gravitationally from the top of the granulator and the product is collected below the matrix. The raw material is forced through the matrix holes by driving only the matrix or optionally separately driving also the roller, these elements are not in contact with each other in case the matrix and the roller are driven simultaneously.
An embodiment of the object of the invention is presented on the drawing on which fig. 1 presents a layout of the apparatus with one container and the fine grinding and/or homogenising section, fig. 2 - a layout of the apparatus with four containers for various raw materials, fig. 3 - the apparatus with two containers, fig. 4 presents the apparatus with four containers and the fine grinding and/or homogenising section, fig. 5 - a perspective view of the flat granulator, fig. 6 shows schematically a cross section of the flat granulator with the "detail A" area marked wheras fig. 7 shows the detail A, i.e. a detailed cross-section view of the punches co-operating with the matrix holes.
Fig. 1-4 shows various variants of the apparatuses comprising the flat granulator which makes the invention innovative. The apparatus according to the invention in its simplest embodiment comprises the raw material container or containers 1, 2, 3, 4, and the flat granulator 10, connected with the aforementioned container(s) by the feeder 5 or feeders 5, 6, 7, 8, as it is shown in fig. 2 and 3.
In a more complex embodiment which is also typical for this branch of industry, the apparatus comprises a container 1 or several containers, e.g. containers 1, 2, 3 i 4 for various kinds of raw materials, the fine grinding and/or homogenisation section 9 and the feeder 11 connecting that section with the flat granulator 10. Such example of the equipment is shown in fig. 1 and 4.
These examples illustrate possible embodiments of the apparatus comprising a flat granulator; however, is is obvious for a professional that other combinations of the a.m. typical, known modules used in the equipment designed for briquetting or granulating solid fuels, i.e. drive units, power supply units, control panels, dust extraction systems, equipment designed to pre-heat raw material or to remove excessive humidity are also possible. Both the aforementioned equipment and the embodiments shown in fig. 1-4 do not constitute the essence of the solution. Its essence is the apparatus equipped with a specifically designed flat granulator, of which the spatial arrangement and the principle of operation ensure an enhanced way of producing solid fuel in the form of e.g. granulate or pellets.
The apparatus for production of solid fuel in the form of pre-formed blocks comprises the flat granulator 10, the exemplary embodiment of which is shown in fig. 5-7. The granulator 10 is provided with the flat matrix 12 with fixing holes 14 and provided with the moulding holes 16 and the kneading roller 13 fixed on the shaft 15 and comprising the punches 17 on its perimeter. The holes 16 have a conical (funnel-shaped) shape in the upper part (adjoining the punches 17) and deep inside the matrix they change over to the cylindrical holes 18. From the lower side of the surface 19 of the flat matrix, the ready formed solid fuel blocks are collected. They can be collected, e.g. into a container with various types of rakes.
Fig. 6 shows the arrow S which indicates the direction of the gravitational downward raw material charge into the flat granulator. The raw material is crushed between the matrix and the kneading roller with the punches. When only the matrix is driven, these two co-operating elements move with the effect of the meshing of the punches with the matrix holes which causes raking of the raw material between the matrix and the roller with the punches and causes crushing of the raw material between the adjoining surfaces of the matrix and of the roller with the punches. In another variant of the invention, the matrix as well as the kneading roller can be driven and then the punches are not required to come in contact with the holes (the drive transmission effect by the meshing of the punches and the holes is not required), which increases the lifetime of the apparatus. The direction of the flat matrix motion (the reciprocating motion) is shown in fig. 5.
Both the matrix and the kneading roller with the punches can be driven independently - the matrix can be connected by the fixing holes with a drive unit and the kneading roller can be connected with such drive unit by means of a propeller shaft or, in another embodiment of the apparatus, only the matrix can be driven which is more preferable and allows the non-driven element to adjust itself freely to the motion of the driven matrix. It is desirable while producing bigger solid fuel blocks.
The matrix has a flat shape but it can be a form of wide flat surface as well as a longitudinal and narrower surface. The kneading roller has a shape of a cylinder and its diameter can be freely adjusted in some measure e.g. depending on the length of the matrix. In another variant of the apparatus it is also possible to equip it with an additional roller with a grooved surface. Such roller can perform the function of stirring, crumbling, grating and additionally homogenising the raw material blend in course of the process. Such thickening roller can also have a surface on which longitudinal toothed projections are set.
The flat granulator can also be equipped not with one but with two or more kneading rollers with punches which is particularly desirable in case of large surfaces of a flat matrix. The rollers are positioned at a proper distance from each other and their rotation axes are parallel.
The apparatus and the method according to the invention are bases on the application of a granulator featuring a special new design which makes it possible to significantly increase the raw material congestion to the form of hard, small size granules (pellets) or to produce larger size cylindrical briquettes, depending on the size of the used punches and holes in the flat matrix.
The raw materials are pressed under the pressure exerted by the punches hitting the matrix holes, which allows achieving greater compaction (increasing the density) of the obtained pellets.
In the apparatus according to the invention, it is possible to use a separate drive of the matrix with holes and the roller with punches, which is preferable while producing small size granules or pellets. It is also possible to use a drive of only the matrix - for larger size briquettes. In that case, the punches become a part of the meshing gear, transmitting motion from one element onto the other while cooperating with the holes in the matrix. The risk of damaging the punches which could occur while producing big pellets with the use of drives both of the matrix as well as the rollers with the punches is reduced.
The holes in the matrix have, in the upper part (adjoining the punches), a conical shape, which widens towards the punches. The holes are further cylindrical. Such shape of the matrix holes allows the occurrence of minimum displacements between the settings of the punches and the holes so as to prevent these differences from causing additional resistance and possible damages of the apparatus in course of the granulator operation. The roller with the punches is made in such way that the length of the punches is not bigger than the depth of the conical part of the holes in the moulding matrix. The punches also have the diameter smaller than the diameter of the conical part of the holes in the matrix. The punches can have a shape of a cylinder or a cut cone. The shape of a conical punch is adjusted to fit the shape of the conical hole in the matrix.
The possibility of adjusting sizes of the matrix holes and the punches as well as changing the type of the drive of the co-operating elements of the granulator allows making granules (pellets) of blends of materials featuring different physical properties, e.g. biomass and coal.
The granulator can comprise a flat matrix with holes situated in any way in a few / several rows with various spacings, designed to suit the kind of the raw material actually processed and resistance occurring in course of the process. The roller with adequately pre-set punches must co-operate with the matrix holes, so the sizes of the holes and the punches, their quantity and location on the perimeter of the roller must mutually correspond.
Positioning of the matrix with holes and the co-operating punches in such way that the raw material is fed into the granulator from the top is preferable and, in combination with the reciprocating motion of the matrix, it ensures the correct arrangement of the raw material in the apparatus and placing the raw material blend between the matrix and the roller with punches so that that forcing of the raw material through the matrix holes is facilitated.
The method according to the invention is used to obtain solid fuel in the form of pre-formed blocks in the shape of granules or pellets. The apparatus according to the invention can comprise a container or several containers for various individual raw materials, i.e. lignite and/or hard coal, biomass, fillers and binders. Individual raw materials are supplied by feeders to a fine grinding and/or homogenisation section and another feeder supplies a homogeneous blend to a flat granulator where the raw material blend is forced by the punches through the holes in the matrix below its level where the product is collected.
In the method according to the invention in the preferable embodiment, it is not required to keep reversing the raw material - the matrix is built up so as to prevent the raw material from escaping from it in any other form than ready formed blocks.
The method according to the invention in the embodiment allows producing granulate (pellets, briquettes), the form of which results from the shape of the round holes of the matrix. In principle, the produced fuel can have any sizes (diameter and length), which are modified depending on raw materials or the pre-set purpose. The pre-formed solid fuel can, for example, have the length of a few / several centimetres or even less than one centimetre. Also, the diameter of the produced blocks can vary from several millimetres to several centimetres.
The granulator can, however, be modified in such a way that it comprises a matrix and adequately adjusted punches which allow producing granulate with cross sections other than circular.
The granulate produced by the method according to the invention can be burnt in any type of boiler with any type of stove. These can be automatic boilers with a retort furnace, boilers with a burner for pellet, fluidised bed boilers used in the power engineering sector, boilers with powdered fuel burners. The solid fuel produced by the method according to the invention is also suitable for being co-burnt with other solid fuels.
Examples of the raw materials used in the method according to the invention are presented below.

Example 1

Lignite dust with the grain size smaller than 50 mm, fed by means of the feeder 5 from the container 1 in the amount of 40 weight %, is blended in the fine grinding section 9 with the hard coal dust fed by means of the feeder 6 from the container 2 with the grain size smaller than 10mm in the amount of 60 weight % until a homogeneous blend is produced. The homogeneous blend is fed by the feeder 11 to the drum granulator where the solid fuel is formed.

Example 2

According to the example 1, granulate was produced from a blend comprising 50 weight % of lignite.

Example 3

Coal dust with the grain size smaller than 50 mm in the amount of 60 weight %, fed from the container 1 or 2, plant biomass with 15% moisture content supplied from the container 3 in the amount of 30 % weight and a mineral binder from the container 4 in the amount of 10 weight % are supplied to the homogenisation section 9 and blended until a homogeneous blend is produced, and then supplied by means of the feeder 11 to the drum granulator 10 where it converted into pellets.

Example 4

The crumbled biomass in the form of milled waste from a woodwork process, along with tree bark with the grain size smaller than 5 mm and low moisture level at approx. 10%, is supplied from the container 3, blended with hydrated lime Ca(OH)2 from the container 4 in the amount of 10 volumetric units in relation to the biomass amount, left for 16 hours and then blended with coal dust (hard coal) from the container 1, in 1:1 volumetric ratio, i.e. in the amount of 50 volumetric units of the coal dust per 50 volumetric units of the biomass in the blend with the hydrated lime; volatile ash from the container 4 is added in the amount of the 5 weight units in relation to the total weight of the coal dust and the biomass in the blend with the hydrated lime and then the produced homogenised blend is fed by means of the feeder 11 to the drum granulator 10 where it is granulated.

Claims

An apparatus for production of solid fuel in the form of pre-formed blocks, comprising at least one container for raw materials, connected with a granulator directly or indirectly by means of a fine grinding section and/or a homogenisation section, characterised in that the flat granulator (10) comprises a flat matrix (12) provided with holes (16) and a movable kneading roller (13) which adjoins it and is provided with punches (17).
The apparatus according to claim 1, characterised in that the holes (16) in the upper part of the matrix (12) have a conical shape which changes over in the further part into a shape of cylinders (18).
The apparatus according to claim 1 or 2, characterised in that the length of the punches (17) is equal to or smaller than the depth of the conical part of the holes (16) and the diameter of the punches (17) is smaller than the diameter of the conical part of the holes (16).
The matrix according to claim 1 or 2 or 3, characterised in that the matrix (12) is connected to a drive unit which sets the matrix (12) in reciprocating motion and optionally the roller (13) is connected by means of a shaft (15) with a drive unit which sets it into rotational motion.
A method of producing solid fuel in the form of pre-formed blocks, comprising the raw material delivery by at least one container and optionally fine grinding and homogenisation of the raw material, characterised in that the fuel blocks are pre-formed in a flat granulator (10) comprising a flat matrix (12) with holes (16) which are situated on its upper surface and through which, by means of at least one kneading roller (13) adjoining it and provided with punches (17) on its perimeter, the raw material is forced through the matrix, wherein the raw material is charged gravitationally from the top of the granulator (10) and the product is collected below the matrix (12).
The method according to claim 5, characterised in that the raw material is forced through the holes (16) of the matrix (12) by driving only the matrix (12) or optionally separately driving also the roller (13), wherein these elements are not in contact with each other in case the matrix (12) and the roller (13) are driven simultaneously.