WO1983001226A1

WO1983001226A1 - An apparatus for producing fuel briquettes

Info

Publication number: WO1983001226A1
Application number: PCT/SE1981/000286
Authority: WO
Inventors: Sven E Olsson
Original assignee: Olsson, Sven, E.
Priority date: 1981-10-02
Filing date: 1981-10-02
Publication date: 1983-04-14
Also published as: AU7647881A

Abstract

An apparatus for producing fuel briquettes comprises a chip-cutter (14), a compactor (16) directly connected thereto and an internal combustion engine (29) driving the same. The residual heat from the engine is utilized in various ways for promoting the sintering conditions of the chips. A first sleeve (32) encloses a portion of the transport tube (17) of the cutter, and the exhaust gases of the engine are brought to pass this sleeve. The cooling water of the engine may be utilized in a further sleeve (37) enclosing an other portion of the transport tube and/or by conducting the air forced through the cooler (40) of the engine to a distributing manifold (43) located between the outlet from the chip-cutter (14) and the inlet (18) to the transport tube. The product obtained will initially be a rod like unit having a hard outer shell, which by means of a further cutter (44) at the outlet end (19) of the transport tube is subdivided into briquettes of suitable thickness.

Description

AN APPARATUS FOR PRODUCING FUEL BRIQUETTES

The siutation upon the fuel market makes it interest¬ ing to utilize raw materials,^" which have hitherto been re¬ garded as waste, or which have suffered from excessive handling costs. Actual raw materials are in the first hand found among the residues left after lumbering and wood thinnings; but also refuse from saw mills, wood industries and building cites. Furthermore peat; straw and combust¬ ible wastes may be. useful.

The raw materials may be transformed into chips or the like; but this will bring about high transport costs, and it will also be difficult to maintain an even moisture content.

The aim of the present invention is to propose an apparatus; which is well suited to produce fuel briquettes from arbitrary raw material.. The briquettes consist of densely compacted matter; which will reduce transport costs,^' and furthermore will burn for a longer time than particulate chips. At many small furnaces it will then be possible to increase the intervals between the occasions for fuel supply.

A rational handling presupposes an efficient combina¬ tion of the units performing the chip-cutting and the com¬ pacting; as well as of the driving means therefor. An apparatus according to the invention is characterized in a chip-cutter for fractionating raw materials into particles of suitable size; a compactor located directly at the out¬ let of the cutter and comprising a transport tube and a reciprocating piston in the compacting cylinder end there¬ of, an internal combustion engine driving the cutter and the piston mechanism, as well as means for transferring residual heat from the engine to the transport tube..

The most important residual heat is found in the ex¬ haust gases of the engine,^' and these gases are conducted through a sleeve; enclosing a portion of the transport tube.

OMPI _Also the heat of the cooling water of the engine may be utilized for instance in a further sleeve enclosing an other portion of the transport tube; preferably close to the in_let end thereof. Alternatively heat can be transfer- red by way of air forced through the cooler of the engine, the heated air being expelled between the cutter and the compactor.

The chip-cutter; the compactor and the internal com¬ bustion engine are preferably mounted upon a platform adapted to be fitted upon a vehicle; the transport tube being arranged in such a manner; that its discharge end is located outside of; and at a higher level than the adjacent side of the platform.

The apparatus can easily be transferred between diffe- rent working cites or consumers; and may all the time being mobile. It should; however,^* preferably be designed so it; at least occasionally; may be located stationary,¹ removed from the vehicle.

The invention will below be descrbied with reference to the accompanying drawings; in which

Figure 1 shows an elevation of the apparatus,^' Figure 2 shows a plan view of the apparatus. Figure 3 shows a detail of the feeding pocket of the com¬ pactor; and Figure 4 shows an alternative embodiment using a number of tubes connected to a common,' compacting cylinder. The raw material may; as is mentioned above, vary within wide limits; but the combination of pressure and heat will provide a final product having about uniform moisture content and with a high density. Wood refuse from ^■coniferous trees has a high content of resin, turpentine and the like. The lignin present in all kinds of wood material will furthermore be transformed when subjected to pressure and heat; as in the present apparatus,' and a rod shaped briquette is obtained; having a "hard sintered" outer shell. This ensures that the briquettes are held to_¬ gether during a -subsequent transport, and do not fall apart into small particles. Experience has shown, that th_j

OM briquettes can be subjected to external moisture, without swelling or breaking up. When straw or dry demolition re¬ fuse are used, it may sometimes be advantageous to add some binder before the compacting. 5 The apparatus shown in Figures 1 and 2 is mounted upon a platform 10, which is designed so as to permit an easy transportation upon a suitable vehicle, for instance a log forwarder, partly denoted by broken lines at 11 in Figure 1. The platform is provided with telescopic support legs 10 12,^" which are" used to stay the vehicle when the plant is in operation, but which will carry the plant separate from the vehicle. Parts of the beam framing 13 of the platform may be designed as tanks for fuel oil and oil for the hydraulic rams. ■ 5 The apparatus includes a chip-cutter 14, which may be of arbitrary known type, here mounted with its axis of rotation horizontally. A compactor 16 of the piston type is fitted directly at the outlet 15 from the cutter. The cutter comprises a transport tube 17, which is arranged so 0 it, from an inlet 18 just below the outlet of the cutter 14 is inclined upwardly, and it extends outside of and above the adjacent side of the platform 10. It will then be easy to arrange a recipient — a conveyor or a hopper - below the mouth 19 of the transport tube. 5 A piston 20, driven by a hydraulic ram 21, is reci- procably fitted in the inlet end of the transport tube acting as cylinder; and will, during a stepwise compacting of the chips falling down through the inlet 18 from the cutter, force the product outwards through the tube. 0 Posssible moisture in the raw material will then be squeezed out, and due to the inclination of the tube it will drain away through openings at the lower end of the tube, or through openings arranged along the tube.

The transport tube may have arbitrary cross section, 5 for instance circular or square. A portion of the tube, just downstream of the inner dead center of the piston, may be designed with a tapering cross section, so as to offer an efficient resistance to the compacting.

OMPl The raw material is fed by a conveyor 22, which in a manner known per se, is provided with a band comprising rods and chains which is supported by a number of rollers 23,^* and is driven by a suitable power source 24, here an hydraulic motor.

The band is enclosed by side walls 25, which guide the raw material towards the inlet of the chip-cutter 14. Adjacent to the inlet thereof there is a lower fixed roller 26, and an upper roller 27, which is hung in swing- ing arms 2 ; and will perform a preliminary compression of the raw material which may be rather "bushy".

An internal combustion engine 29, preferably a diesel engine, supplies power to the various components as well as the heat needed during the compacting. The cutter is driven by way of a belt transmission 30, and a hydraulic pump 31 is mounted directly at the engine. The hydraulic pump supplies pressure fluid to the hydraulic ram 21 of the compactor; as well as to the motor 24 of the conveyor. An electric generator, as well as inventional control means are not shown; as they form part of a well known technique. ,.

Of interest from the point of view of the invention are the arrangements for utilizing the waste heat of the engine for heating the process material. A sleeve 32 en- closes a portion of the transport tube 17, and the exhaust pipe 33 of the engine is connected to this sleeve. The gases pass out into the atmosphere through an upwardly directed pipe 34. When starting the plant in cold weather, or when the atmosphere is humid, it may be advantageous to aid the heating, so the production can commence rapidly. The sleeve 32 therefore is provided with a fitting 35 for mounting a gaseous fuel burner 36 (indicated in broken lines) or the like.

A second sleeve 37 is fitted around an other portion of the transport tube 17, closer to the inlet thereof than sleeve 3?.. At least part of the cooling water of the engine is brought to pass this second sleeve by way of a conduit 38 from the cooling water pump 39. The engine is provided with a cooler 40, which in a conventional manner is provided with a fan 41. The air forced through the cooler is conveyed through a conduit 42 to the passage between the cutter and the inlet 18 to the transport tube; and is disitributed through a manifold 43. Such an arrangement is shown in Figure 3. Two square- section transport tubes 17a, b are arranged in parallel, and the manifold 43 extends in parallel thereto within the outlet 15 of the cutter; and is provided with suitably lo- cated outlet slots..

The piston mechanisms in the two parallel tubes may be coordinated so one piston 20 moves inwards, while the other moves outwards.

The compacting and heating transform the chips to a continuously advancing rod like unit, which is expelled at the mouth of the transport tube. This rod will break due to its own weight, when a certain length of the rod pro¬ jects freely from the mouth. In order to obtain a uniform thickness of the briquettes a cutting device 44 is prefer- ably fitted at the mouth of the tube, and comprises a knife means 44 which is operated by any suitable power source and intermittently cuts the rod.

In order to ensure that the matter to be compacted is efficiently heated it will be favourable to arrange a number of transport tubes 17 in parallel, all advantage¬ ously connected to a common compacting cylinder.

Figure 3 denotes in broken lines a further pair of transport tubes 17c, d, located below the first pair of tubes 17a, b. Figure 4 shows part of an arrangement, where four transport tubes are connected to a common compacting cylinder 50,^" which has the same external dimensions as the group of four transport tubes. Those are mutually separa¬ te'^1" just outside of the inner dead center of the piston stroke. This is in Figure 4 denoted by .the line 51, which de ines the inward end of the compacted matter rod 52.

The piston 53 is shown during its return stroke, and - its front face is thus located at a distance from the end 51 of the co oacted matter. The outer walls of the

OMPI transport tubes 17a - d form extensions of the walls of the compacting cylinder 50. A restriction of the total transport area is obtained by the passages 54, which sepa¬ rate the transport tubes. These passages make it possible for the heating fluid within the sleeves 32, 37 to flow around all side faces of the tubes.

The ends of the passages 54 turned towards the com¬ pacting cylinder are closed by knife members 55, which di¬ vide the matter preliminary compacted by the piston 53, and direct the flow of matter to the individual transport tubes 17a - d. This transfer may mean a considerable throttling, and in order to facilitate the introduction into the individual tubes 17a - d the piston is provided with four pointed projections 56, located centrally with respect to longitudinal axes of the tubes. These projec¬ tions will leave voids 57 within the matter just outside the inlets to the individual tubes, when the piston re¬ tracts. These voids will be filled when the parted mass is forced into the tubes, and they will further facilitate a draining of moisture within this chritical part of the transport path.

^• The amount of chips leaving the cutter is mixed with air and all the way during the passage through the tubes, air will be forced out. The heating will further generate a certain amount of gases and it is advantageous to pro¬ vide airing holes 58 in the tube walls at a distance from the cylinder 50.

The embodiment above described and shown in the drawings is an example only, the details of which may be modified in many ways within the scope of the appended claims.

The binders, or sintering aids, which may be needed with certain raw materials are preferably supplied by way_. of pipe 42 or the manifold 43. As is evident from the specification above a number of transport tubes may be arranqed in parallel and according to various patterns, two or three a-breast or located as indicated in Figure 3.

Claims

CLAIMS 1. An apparatus for producing fuel briquettes by compacting particulate material, and comprising a chip- cutter (14) for fractionating raw materials into particles of desired size, a compactor (16) located directly down- stream of the cutter and comprising a transport tube (17) and a piston (20) reciprocable in a cylinder part thereof located at the inlet end of the tube, as well as means (32, 37) for heating the tube (17), c h a r a c t e r i ¬ z e d in "that the- chip-cutter (14), the compactor (16) and an internal combustion engine (29) driving the same are mounted upon a platform (10) adapted to be fitted upon a vehicle (11), the internal combustion engine (29) being located so as to permit an easy heating of the transport tube (17), the outlet end (19) of which extends outside of, and above the adjacent side of the platform.

2. An apparatus according to claim 1, c h a r a c ¬ t e r i z e d in that the transport tube (17) is partly enclosed by a sleeve (32, 37),^' and that heating of the tube occurs by the exhaust gases and/or the cooling water of the engine being brought to pass said sleeve.

3. An apparatus according to either of the claims 1 or 2, c h a r a c t e r i z e d in a heat exchanger (40) for the cooling water of the engine and a conduit (42) for transferring heat carried by air and connected to a mani- fold (43) between the chip-cutter (14) and the inlet (18) to the compactor.

4. An apparatus according to any of the preceeding claims, c h a r a c t e r i z e d in that at least two . transport tubes (17a - d) are connected to the same com- pactinq cylinder (50) and over a major part of their lenqths are separated by passages (54) permitting the heating fluid passing the enclosing sleeve (32, 37) to contact the tubes all around.

^~

5. An apparatus according to claim 4, c h a r a c ¬ t e r i z e d in knife means (55) directed towards the common compacting cylinder (50) and arranged to terminate the ends of the passages (54) turned towards the cylinder, reaching about to the inner dead center (51) of the piston (53), the latter being provided with pointed projections (56) located centrally with respect to the longitudinal axes of the tubes (17a - d) , and reaching beyond the knife means (55) when the piston is at its inner dead center.