EP2548723A1

EP2548723A1 - Device for producing solid fuel in a form of shaped profiles and method for producing solid fuel

Info

Publication number: EP2548723A1
Application number: EP12005064A
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: PL395693A1

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 ring granulator (10) comprises a ring matrix (12) provided with holes (16) and at least one kneading roller (13), located inside, adjoining it and provided with punches (17) on its perimeter, the matrix (12) rotation axis being parallel to the roller (13) rotation axis. The invention also relates to a 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 PL174972 , 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 ring granulator comprising a ring matrix provided with holes and at least one kneading roller, located inside and adjoining the matrix, provided with punches on its perimeter, the matrix rotation axis being parallel to the roller rotation axis; the holes have a conical shape from the internal side of the matrix and then a shape of cylinders in the external part of the matrix. 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 apparatus is provided with at least one stirring roller 13a and/or at least one consolidating roller 13b. The granulator is driven by a propeller shaft while the rollers do not have their own drive and move freely, adjusting their rotational motion to the motion of the driven matrix.
The object of the invention is also the method of producing solid fuel in the form of pre-formed blocks, comprising delivery of the raw material by 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 ring granulator comprising a ring matrix, driven by a shaft, provided with holes through which, by means of at least one kneading roller adjoining it from the inside and provided with punches on its perimeter, raw material is forced out of the matrix, the raw material being charged into the matrix. The raw material is stirred and/or consolidated in the matrix by means of the stirring roller or the consolidating roller.
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, 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 ring granulator in the side view with two kneading rollers provided with punches, fig. 6 shows a cross section of the ring granulator variant from fig. 5, fig. 7 - a cross section of the ring granulator with one kneading roller provided with punches, fig. 8 presents the detail B from fig. 6 and 7, fig. 9 shows a cross section of a variant of the ring granulator with one kneading roller and one plain roller without punches, and fig. 10 presents a perspective view of the granulator provided with one kneading roller and one consolidating roller with notches on its perimeter.
Fig. 1-4 shows various variants of apparatuses comprising the ring 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 ring granulator 10 connected with the aforementioned containers by one feeder 5 or feeders 5, 6, 7, 8. Such variants of the apparatus are shown in figs. 2 and 3.
In a more complex embodiment which is also typical for this branch of industry, the apparatus comprises the 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 ring granulator 10. Such example of the apparatuses is shown in fig. 1 and 4.
These examples illustrate possible variants of the apparatus comprising a ring 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 examples shown in fig. 1-4 do not constitute the essence of the solution. Its essence is the apparatus equipped with a specifically designed ring 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 ring granulator 10, the exemplary embodiments of which are shown in fig. 5-10.
The ring granulator 10 in the simplest embodiment shown in fig. 7 is provided with the ring matrix 12 fixed on the drive shaft 14 and provided with forming holes 16 and the kneading roller 13 which is located inside the matrix, fixed on the fixing shaft 15 and comprises the punches 17 on its perimeter. The holes 16 have a conical shape in the internal part (the part adjoining the punches 17) and deep inside the matrix they change over to the cylindrical holes 18. Fig. 8 shows in detail the mutual arrangement of the punches and the holes 16 as well as the principle of their co-operation. From the external side 19 of the ring matrix, the ready formed solid fuel blocks are collected. The fuel blocks can be collected by various feeders and rakes known to specialists professional in this field. Inside the matrix 12 there is a space, which constitutes the internal chamber 20.
Fig. 5 and 6 present the exemplary ring granulator 10 provided inside with the two kneading rollers 13 and 13' which are fixed, preferably symmetrically, on the fixing shafts 15 and 15' respectively.
Fig. 9 shows another embodiment of the ring granulator 10 in which the ring matrix 12 is provided inside with the kneading roller 13 and the plain roller 13a which performs the function of grating, consolidating and fine grinding of the raw material.
Fig. 10 presents another, exemplary embodiment of the ring granulator 10 in which the ring matrix 12 is provided with the kneading roller 13 and the consolidating roller 13b situated inside the matrix, the consolidating roller 13b being provided with longitudinal parallel grooves. The consolidating roller can alternatively have longitudinal serration or notches on its surface so as to ensure stirring and possibly grating and find grinding of the raw material inside the matrix.
Fig. 5 shows the arrow S, which illustrates the direction of the raw material charge into the ring granulator. The raw material is crushed between the internal wall of the matrix and the roller or rollers with punches. There may be a few, e.g. three or four kneading rollers inside the matrix. These co-operating elements (i.e. the matrix and the kneading rollers) move in a mutually consistent direction (the result being the meshing of the punches in the holes of the matrix). The directions of the rotation of the matrix and the kneading rollers are exemplified by means of arrows in fig. 5 and fig. 10. The rotational motion of the elements of the granulator causes capturing of the raw material between the matrix and the roller with the punches and causes forcing of the raw material through the holes of the matrix.
The ring matrix is driven by the shaft 14 which makes the rollers 13, 13', 13a or 13b on the fixing shafts 15 rotate which allows them to adjust themselves freely to the motion of the ring matrix. Eliminating the drive of the kneading rollers is particularly preferable while producing larger size blocks of the solid fuel. 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 kneading rollers with the punches is reduced. Both the ring matrix and the rollers have a cylindrical shape, however their diameter may be freely adjusted in some measure.
The apparatus and the method according to the invention are based on the application of a ring 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 set on the kneading rollers and the holes inside the ring matrix. The homogeneous raw material blend is pressed under the pressure exerted by the punches hitting the matrix holes, which allows achieving greater compaction (increasing the density) of the produced pellets.
The holes inside the matrix have, within the part contacting 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 in course of the granulator operation. The roller or rollers with the punches are 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 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 the specific type of the granulator drive allows making granulates (pellets) from blends of materials featuring different physical properties, e.g. biomass and coal.
The granulator can comprise a ring 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 kneading 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.
The setting of the matrix with the holes and the co-operating punches in such a way that the granulator is fed with the raw material into the matrix additionally performs the function of homogenising the raw material blend so that pressing the material through the matrix holes is facilitated.
The design of the ring granulator in the variants shown in fig. 9 and fig. 10 is modified by adding the stirring roller 13a or the consolidating roller 13b. The consolidating roller 13b is provided with grooves so that its surface is toothed. It causes a preferable effect of blending, grinding and grating of raw materials in the ring matrix.
For a professional in a given field it is obvious that the design of the granulator can be modified in such a way that it comprises at least one kneading roller and e.g. in various variants an additional stirring and/or consolidating roller or it comprises three kneading rollers with punches and one consolidating roller, etc.
The method according to the invention is used to produce 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 the ring granulator where the raw material blend is supplied into the matrix and is forced by the punches through the holes in the matrix outside where the product is collected, in the form of granules, pellets.
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 also 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 annular 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 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 annular 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 ring granulator (10) comprises a ring matrix (12) provided with holes (16) and at least one kneading roller (13), located inside, adjoining it and provided with punches (17) on its perimeter, the matrix (12) rotation axis being parallel to the roller (13) rotation axis.
The apparatus according to claim 1, characterised in that the holes (16) on the internal part of the matrix (12) have a conical shape and then in the external part of the matrix (12) they have 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 apparatus according to claim 1 or 2, characterised in that it is provided with at least one stirring roller 13a and/or at least one consolidating roller 13b.
The apparatus according to claim 1 or 2, characterised in that the granulator (10) is driven with a propeller shaft (14) whereas the rollers (13), (13'), (13a) and (13b) do not have their own drive system.
A method of producing solid fuel in the form of pre-formed blocks, comprising delivery of the raw material by at least one container and optional fine grinding and homogenisation of the raw material, characterised in that the fuel blocks are pre-formed in a ring granulator (10) comprising a ring matrix (12), driven with a shaft (14), provided with holes (16) through which, by means of at least one kneading roller (13) adjoining it from the inside and provided with punches (17) on its perimeter, raw material is forced out of the matrix, wherein the raw material is charged inside to the matrix (12).
The method according to claim 5, characterised in that the raw material is stirred and consolidated in the matrix (12) by means of the stirring roller (13a) and/or the consolidating roller (13b).