CH680798A5 - Fuel briquette - made from waste wood prods. with other waste materials, crushed and dried before shaping - Google Patents

Abstract

The fuel briquette, based on wood, contains between 5 and 75 per cent of combustible waste material and is produced without the addn. of binding agents. After the wood, e.g. in the form of chips or sawdust, has been mixed with the waste matter, which can be of paper, straw or household waste, the mixt. is crushed and dried to reduce its moisture content to less than 15 per cent, and then compressed into shape. The mixt. can be passed through a metal detecting process before crushing, and the mixt. can be ground to give it an even consistency. Before crushing and/or after drying, the material can be screen, and prior to drying it can be stored in a silo. All of the processes can be automatically controlled, and carried out ina plant with a loaded, conveyor, a crusher, a drier, and moulder, with silos to store the prods.. ADVANTAGE - More productive use of waste materials, providing useful fuel.

Description

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CH 680 798 A5

Description

The present invention is in the fuel sector and relates more particularly to a briquette based on a mixture of wood and waste such as paper, straw and household waste for example. It also extends to a method for manufacturing the latter and to an implementation means.

Wood-based agglomerates are already known, generally having the shape of a log, which are used to supply the fireplaces.

To reduce the nuisance caused by the increase in household waste and its transport to incineration centers, the present invention proposes to mix it with wood, and even wood waste such as shavings and sawdust either sawmills or other wood-working factories, that is to say brush collection, dead branches and twigs and pieces of bark abandoned in the forest by loggers. The use of these has the additional advantage of cleaning the forests, which also ensures better vegetation.

Such a briquette must be used in a burner reaching a temperature of the order of 1100 ° C, or even more, to avoid the emission of dioxins and comply with the standards in force.

The subject of the invention is a mixed briquette made from wood, characterized in that it also comprises from 5 to 75% of combustible waste, without the addition of binders.

The invention also extends to a process for manufacturing a mixed briquette, characterized in that 5 to 75% of combustible waste is mixed with wood, the mixture is crushed, the materials are dried to bring the content in water at a maximum of 15% humidity and the materials obtained are pressed to amalgamate and shape them.

Intermediate steps can be carried out without departing from the scope of the invention, for example to detect the presence of metals, to filter the materials, to carry out additional grinding of the dried materials, to obtain a constant grain. Materials can also be stored between certain stages, to regularize the sequence of operations.

The invention further extends to a means of implementing the method described comprising means for loading, mixing and controlling the materials to be treated; conveyor means for transporting materials between the different work stations; crushing means; drying means; pressing means and command and control means of operation.

This implementation means can also include means for complementary grinding of the dried materials, storage means, and / or filtering means. The means for monitoring materials include, for example, a metal detector.

In addition, the drying installation may include a boiler using the mixture of materials according to the invention as fuel, at the outlet of the drying filter.

The movements of the materials are made by any known conveyor system, such as chain conveyor, bucket conveyor, worm conveyor or vibrating conveyor.

The accompanying drawing shows, by way of nonlimiting example, an installation for manufacturing a briquette according to the invention.

The single figure provides a schematic top view of an installation of the device for implementing the briquettes.

The main components of the device according to the invention are:

- Means 1 for loading, mixing and controlling the materials to be treated;

- conveyor means 2 for transporting materials between the different work stations,

- crushing means 3,

- storage means 4,

- drying means 5,

- grinding means 6,

- pressing means 7,

- means of command and control of the operation.

The means 1 for loading and controlling the materials to be treated are composed of a vibration feeder 11, into which the materials are introduced after manual elimination of non-combustible waste such as cans, bottles, etc. Mixing can be carried out either from automatic silos or by direct dumping.

A first vibration conveyor 21 conveys the materials towards a metal detector 12, allowing the location of any metallic body with a volume greater than 1 dm3. A sieve 13 makes it possible to separate the small particles of material before introduction into the crushing means 3 adjusted so that the maximum volume of the pieces is of the order of half a cubic centimeter.

A second conveyor 22 brings the materials into a first silo 41, where the wet materials are stored, which will be extracted by a hydraulic system 42 for advancing the bottom intended to bring the materials to an advance screw 43 ensuring the load of a scraper conveyor 23 conveying the materials to the drying means 5. Storage of the materials is not essential, but it nevertheless makes it possible to regulate the supply of the dryer.

A magnetic particle separator 51 is disposed before a feed screw 52 conveying the materials to a drying drum 53 and a cyclonic tower 54 for separating the dry materials. Part of the dried material is then used as fuel for the drying plant and

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CH 680 798 A5

is brought back to the boiler 55 along a conveyor belt 24, while the majority of the dried materials are extracted by an endless screw 61 to a vibration screen 62, for the separation of large particles after drying. A complementary grinder 63 is provided to ensure a constant grain of the materials, which, by a scraper conveyor 25, are brought to a second silo 46 where the dry materials are stored, which are extracted by a hydraulic system 47 of bottom feed intended to bring the materials to a feed screw 48 ensuring the load of a scraper conveyor 26 conveying the materials to the press 7.

The pressing assembly 7 comprises a separator 71 intended to remove the metal particles before the presses, a feeder 72 with two downspouts to ensure the simultaneous supply of two briquetting presses 73 exerting a pressure of the order of 500 kg per centimeter square, to agglomerate materials, without adding binders. We can also consider feeding up to 10 presses simultaneously, depending on the dimensions of the installation. The cylinders of agglomerated material advance along tracks 74 before being cut to the desired length by means of saws 75, then transported to the packaging station by a roller conveyor, not shown.

As already mentioned, the installation also includes automatic control and regulation devices, ensuring the operation of the various assemblies described so far, whether they are electrical elements, such as the various motors shown diagrammatically in drawing, or hydraulic components.

It should also be noted that the means for implementing the method shown in the drawing is given by way of example only, and that modifications to the installation described are possible without departing from the scope of the invention.

By way of comparative example, the density and the calorific power of wood-based briquettes or mixed briquettes according to the invention comprising 50% of wood and 50% of household waste are given in the following table:

density

power calor wood-based briquette

1.3

4 to 5kW

mixed briquette

1.1

2 to 3kW

Claims (17)

Claims 1. Mixed briquette made from wood, characterized in that it also comprises from 5 to 75% of combustible waste, without the addition of binders. 2. Method of manufacturing a mixed briquette, characterized in that 5 to 75% of combustible waste is mixed with wood, the mixture is crushed, the materials are dried to bring the water content to a maximum of 15 % humidity, and the materials obtained are pressed to amalgamate and shape them. 3. Method according to claim 2, characterized in that the presence of metals is detected before the crushing operation. 4. Method according to claims 2 to 3, characterized in that one performs a complementary grinding of the dried materials, to obtain a constant grain. 5. Method according to claims 2 to 4, characterized in that the materials are filtered before crushing and / or after drying. 6. Method according to claims 2 to 5, characterized in that the crushed mixture is stored in a silo, before the drying operation. 7. Method according to claims 2 to 5, characterized in that the dried mixture is stored, before the amalgamation and shaping operation. 8. Method according to claims 2 to 7, characterized in that the drying installation is supplied with dried materials. 9. Method according to claims 2 to 8, characterized in that the operations are automatically controlled. 10. Means for implementing the method according to claim 2, characterized by means (1) for loading, mixing and controlling the materials to be treated; conveyor means (2) for transporting materials between the different work stations; crushing means (3); drying means (5); pressing means (7) and operating command and control means. 11. Means of implementation according to your claim 10, characterized in that the control means comprise a metal detector (12). 12. Means of implementation according to claim 10, characterized by complementary grinding means (6) of the dried materials. 13. Implementation means according to claim 10, characterized by filtering means (13,62). 14. Implementation means according to claim 10, characterized by silos (41, 46) constituting storage means (4) of the materials. 3 5 10 15 20 25 30 35 40 45 50 55 60 65 CH 680 798 A5 15. Implementation means according to claim 10, characterized in that the drying means (5) comprise a drying drum (53), a cyclonic tower (54) and a boiler (55). 16. Implementation means according to claim 15, characterized by a belt conveyor (24) between the outlet of the cyclonic tower (54) and the boiler (55), for the supply thereof with fuel. 17. Means of implementation according to claim 10, characterized in that the pressing means consist of 1 to 10 presses fed simultaneously. 4