DE2432487A1 - Conveyor system with conveyor screw - Google Patents

Description

Walter Rüegsegger 8o44 Zurich / Switzerland

Conveyor system with a screw conveyor

The present invention relates to a conveyor system with a screw conveyor on firing device for with time itself Solid fuel, in particular wood waste, accumulates due to changing volume weights.

For example, in order to achieve as complete a combustion as possible in furnaces _} the fuel introduced into the furnace and the amount of combustion air must be in a predetermined ratio that is as constant as possible. Conventional conveyor systems feed such firing systems with a certain density of fuel by means of screw conveyors. Since in the fuel bunkers, which the conveyor

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Snails extract the fuel from wood waste, mostly different types of such wood waste Arbitrary, i.e. poorly mixed and often in layers, such as light wood shavings and heavy Sawdust, these known conveying systems mostly convey fuels with strongly changing specificities at short intervals Density in the furnace. The same combustion chamber and the predetermined amount of combustion air are therefore available a strongly changing amount of fuel compared to. the Furnaces are alternately over- or under-loaded with fuel, the good mixing of the combustion gases with the combustion air rarely occurs and the furnace temperature is therefore often too low. This leads to the well-known, inadequate incineration plants,! dykes no longer meet the requirements for environmental protection. Furthermore, there is a risk of burn-back in such systems from the furnace to the chip bunker.

A machine for pressing plastic masses has become known (DT-PS 63923). It also has a pressing element. This press member is inside the bale chamber. This pressing member within the pressing chamber can therefore only be used for pressing thin liquid plastic Masks are used, because that from a compression chamber

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compressed material pushed out with an upstream pressing member cannot possibly be placed under a rotatable surface in the Pressing chamber firmly anchored pressing organ are pushed through, as this already compressed to a certain volume The material to be pressed is already too firm.

This embodiment, which shows a machine for dewatering plastic masses, is therefore for the invention Purpose useless.

In DT-PS 591 629 the compression of the fuel takes place in that the combustion tube and the screw move according to their Taper the outflow. This type of compression of the fuel results in a non-uniform fuel volume weight. Because the fuel is compressed according to the tapering of the screw and the burner tube and not according to the counterpressure of a press member connected downstream of the chamber. The compression takes place exclusively corresponding to the taper of the burner tube. It cannot be set or changed. It takes place So there is no equalization of the volume weight, but only an even reduction of the fuel volume.

The present invention aims to provide a

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Conveyor system, which largely eliminates this disadvantage caused by the changing density of the fuels and which invention improves the burn-back safety of the conveyor system.

The conveyor system according to the invention is characterized by a device for compensating for the changes in volume weight of solid fuel.

Execution examples of the subject matter of the invention are then given explained using purely schematic figures.

Show it:

1 shows a longitudinal section through a conveyor system with a slide arranged in front of the fuel chamber outlet as well as a combustion chamber covered by a second slide.

FIG. 2 shows a longitudinal section through the conveyor system of FIG. 1, with the first slide pulled out and opened Firebox.

FIi .. ~; iaen analogous longitudinal section through a conveyor system

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Pig. 1, with the first slider pressed on and one Press piston for pre-pressing the fuel in the press chamber.

Pig. 4 shows a floor plan of the conveyor system according to FIG.

5 with a longitudinal section through another conveyor system in front of the fuel chamber outlet arranged slide as well as a mounted in front of this slide with spring ring provided with resilient tongues for compressing the transported wood chips as well as with a Firebox covered by a second slide.

6 shows a longitudinal section through the conveyor system according to FIG. 5 in the feed state, immediately before their shutdown when the upper fuel level in the combustion chamber is reached,

The conveyor systems shown in FIGS. 1-4 have a conveyor screw 1 which is mounted in a conveyor trough 2 is. The conveyor trough 2 sits either directly (according to FIGS. 1, 2 and 4) or via a chute 27 (according to FIG. 3) in a pressing chamber 4. The pressing chamber opens into a furnace 3. The screw 1 ends in front of the

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Press chamber 4. In this chamber 4, the fuel conveyed by the screw 1 through this screw 1 itself or compressed by a piston 24 (Fig. 3). So that no immovable plug can form in the chamber 4 the chamber 4 widens conically towards its exit. To the Pressing wood waste with varying volumetric weight in chamber 4 is located in front of its exit Slide 5, which closes the chamber 4 against the furnace side. A roller 6, which by a spring 7 (Fig. 1 and 2) is loaded, rests against the slide 5 and holds it against the force of the fuel to be compressed in the chamber 4 in closed position. In addition to or instead of the loaded roller 6, a counterweight 25 (FIG. 3) can be provided. By Adjustment of the spring 7 or the counterweight 25 can adjust the pressing force acting on the slide 5 as required to enable the appropriate setting of an optimal density of the fuel. The role 6 is fastened in a holder 8, which at the same time partially covers the combustion chamber 3 and is displaceable in a guide 9 is stored. The slide 5 is in guides 10 and 11 and on a push rod 12 of a push motor 13 slidably attached. The push rod 12 is provided with a retaining ring 14. When extending the push rod 12 from the thrust motor 13, the retaining ring 14 presses on a

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Spring 15, which in turn pushes the slide 5 against the meanwhile Pushes the end of the fuel pin ejected from the chamber 4. The free end of the slide 5 is as Cutting edge formed so that when the slide 5 is pushed down, the one emerging from the chamber 4 Separated fuel pin at the exit of the chamber 4 and the Chamber is closed by the slide 5. If, for example, the slide due to a foreign body in the If fuel cannot cut through this, the spring 15 is compressed and there is no blockage of the thrust motor 13 »still a permanent deformation or a breakage of a component of the conveyor system. Of the The thrust motor 13, on the one hand, is attached to a bracket 16 so as to be pivotable.

A limit switch 17 is located above the guide 9 to the roller 6. If the slide 5 and thus the holder 8 are switched off pushed back by the exiting fuel from the chamber 4 against the pressure of the spring 7, the actuates the Slide 5, after a certain pivoting position (FIG. 3), the limit switch 17 »which switches on the thrust motor 13. Together with this thrust motor 13 also switches on a further thrust motor 23, the one connected to it, second slide 18 closing the combustion chamber at the top

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j withdraws so that access to combustion chamber 3 is free. To When the slide 5 is pulled up, it is again pressed into its closed position by the spring 7 with respect to the pivoting angle (Vertical position according to FIG. 2), but is located above the fuel plug emerging from the chamber. Of the The thrust motor 13 is set in such a way that the slide 5 immediately returns to its normal position after it has been pivoted back pushed into the starting position in front of the outlet of the bale chamber * J w.ird and in the process cuts off the fuel tap explained above, which enters the combustion chamber 3 falls.

This fuel replenishment continues automatically until the fuel filled in the combustion chamber presses on a swivel flap 19, which actuates a switch 21 via a lever 20. As a result, the fuel delivery is interrupted until the fuel has burned down accordingly, whereupon the flap 19 is relieved and swings back again into its horizontal starting position. In the embodiment according to FIGS. 1 and 2, the fuel is conveyed and pressed in the pressing chamber 4 by means of the screw 1, whereas in the embodiment according to FIG. 3 the compression of the fuel to a volume weight as uniform as possible is provided by the piston 2k is.

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The system described is extremely simple in its structure and therefore reliable in operation. It allows despite the occurrence of different Volume weights in the conveyor system feeding a largely constant amount of fuel per unit of time, so that the combustion can take place with the optimal composition.

The fuel compressed in the conveyor system naturally offers excellent protection against burn-back the furnace back into the fuel bunker.

Compared to conventional conveyor systems, the following innovations are particularly worth mentioning:

The arrangement of a pressing chamber directly above the furnace for uniform pressing is irregular and inhomogeneous accruing fuel, the compression either directly with the screw conveyor or by means of a special piston pneumatically, hydraulically, electrically or mechanically can be done »

The compression ratio of the resulting fuel can be changed, easily accessible from the outside.

In order to prevent the chamber from blocking after the combustion

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to prevent substance, the chamber is towards its outlet . slightly flared.

When the corresponding set fuel density is reached or when the set opening force occurs, the slide is swiveled out of its normal position, pulled up, swiveled back into its normal position and afterwards pushed down, with the sliding-closing movement simultaneously removing the protruding fuel plug from the rest Separates fuel in the chamber 5. Through synchronization the opening movement of the closing slide 18 of the furnace 3 and the ejection of the fuel and the movement of the closing and cutting slide. 5, the combustion chamber 3 with the fuel bunker is only over a very short one Time span directly connected.

A special sensor, designed as a flap, switches off the conveyor system as soon as the combustion chamber reaches a certain level Fuel level is full. After falling below a certain lower level, the fuel supply switches, controlled through this flap, back on. A corresponding resilient connection between the thrust motor and slide is impossible a deformation of these parts as a result of solid foreign bodies in the cutting plane of the closing chamber

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Slide, so that blocking of the thrust motor cannot occur either. Since in this case no fuel into the combustion chamber through the fuel pumping _s falls further and the slider when the foreign body is completely expelled from the chamber through the cut Brennstoffpfropfen.

The system can only be switched in such a way that, when the conveyor system itself is at a standstill, the chamber outlet through the Slider is definitely covered.

In contrast to the conventional conveyor systems, which have a set volume quantity per unit of time with variable Promote volume weight, it is possible with this system described to practically a set volume amount with constant weight, i.e. to obtain a fuel with constant density and to feed it into the combustion chamber. This also ensures optimal combustion, practically without any traces of smoke. A surveillance the fuel delivery is no longer necessary with such a conveyor system. As with the previously known, purely volumetric conveying systems a constant adjustment with regard to the amount of fuel and the amount of combustion air to achieve this optimal combustion conditions are necessary and very difficult

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was borrowed, this adjustment was usually not with the necessary Carefully carried out or not carried out at all. The present invention provides a remedy here.

The conveyor system shown in FIGS. 5 and 6 has a • Conveyor screw 41, which is mounted in a conveyor trough 42. The conveyor trough42 sits directly in a press chamber 44 away. This chamber 44 opens into a combustion chamber 43 · Die The screw 4l ends in front of the pressing chamber 44. In this chamber 44, the fuel conveyed by the screw 41, for example Wood chips, sawdust and the like, pressed together in a mixture by this screw 41 itself. So that in the Chamber 44 cannot form an immovable plug, the chamber 44 is widened conically towards its exit. To the Pressing wood waste with varying volumetric weight in the chamber 44 to a more uniform volumetric weight is located Immediately in front of the conical widening there is a spring ring 69 with spring leaves inclined towards the chamber axis, which taper conically towards the exit of the channel cross-section and thus the propulsion of the wood waste through the Oppose screw 41 a corresponding resistance. This has the effect of compressing the elements produced by the screw 41 transported wood waste to an extent that is dependent on the tension of the leaf springs of the spring ring 69. These

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Tension can be adjusted to a certain extent. It is also possible to adapt this pressing force to the material to be conveyed by exchanging the peder ring 69. At the exit of the conical chamber 44 there is a slide 45 which closes the chamber 44 against the combustion chamber side. A roller 46 which is loaded by a spring 47 _s is applied to the slide 45th By adjusting the spring 47, the force acting on the slide 45 can be adjusted as required. The roller 46 is fastened in a holder 48 which at the same time partially covers the combustion chamber 43 and is slidably mounted in a guide 49. The slide 45 is slidably fastened in guides 50 and 51 and on a push rod 52 of a push motor 53. The push rod 52 is provided with a retaining ring 54. When the push rod 52 extends out of the push motor 53, the retaining ring 54 acts on a spring 55, which in turn sends the slide 45 against the end of the fuel pin pushed out of the chamber 44. The free end of the slide 45 is designed as a cutting edge, so that when the slide 45 is pushed downward, the fuel strand emerging from the chamber 44 is cut off at the outlet of the chamber 44 and the chamber is closed by the slide 45. This position is shown in FIG. It immediately follows the position according to Fig 6 _0, · in which the allowable fuel level is reached in the combustion chamber and the thrust motor '53 is in the Sehlusssteliung'gesteuert,' _ is set forth subsequently "

For example, if the slide 45 cannot cut through a foreign body in the fuel material, will the spring 55 is compressed and there is neither one Blockage of the thrust motor 53 still a permanent deformation or breakage of a component of the conveyor system. The thrust motor 53 for its part is on a bracket 56 pivotally attached.

Above the guide 49 to the roller 46 there is a limit switch 57.When the fuel is ejected from the chamber and runs up on the slide 45, this, and with it the holder 48, is counteracted by the fuel emerging from the chamber 44 against the pressure of the spring 47 pushed back. After a very slight pivoting, the slide 45 then actuates the limit switch 57, which switches on the thrust motor 53. Simultaneously with this thrust motor 53, a ⁱ further thrust motor 63 is turned on, the one connected to it, second, retracts the firing chamber after final bottom slide 58, so that the access is free zumFeuerraum 43rd After the slide 45 has been pulled up, it is again pressed into its closed position by the spring 47 with respect to the pivoting angle. The slide 45 is, however, located above the fuel line emerging from the chamber 44. Now , in accordance with the continuously rotating screw 41, the fuel train is pushed forward, where it passes through the

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Leaf springs of the peder ring 69 'is pressed together in a predetermined manner and is conveyed in this state with more or less open leaf springs according to FIG. 6. The fuel is therefore compressed to a predetermined volume weight. The strand leaves the chamber 44 or the leaf springs of the spring ring 69 and continues to move in the horizontal direction _s until it hits a wall of the combustion chamber designed as an Abierikwand 68 and disintegrates in the sense of FIG. 6. It then reaches the combustion chamber, as can be seen in FIGS. 5 and 6.

This fuel supply is automatically and continuously continues until the fuel filled in the combustion chamber presses on a pivoting flap 59, which has a Lever 60 actuates a switch 61. As a result, the fuel delivery is interrupted until the fuel is appropriately has burned down, whereupon the flap 59 is relieved and swings back again into its horizontal starting position.

In this way, it is possible to keep the fuel discharged from the press chamber 44 and compressed and to drop regularly in terms of quantity into the furnace or combustion chamber, which is caused by the intermittent work

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is sometimes not possible. With certain fuels but does this play a role; because in the interval-like mode of operation of the slide 45, the fuel falls in short Intervals concentrated in the combustion chamber, this intermittent fuel supply leads to jerky fluctuations in the ideal ratio between combustion air and fuel. This is inconvenient.

Such disadvantages, as they occur with certain fuels, are largely reduced by the present embodiment, since the ejected from the pressing chamber 44 Fuel plug ^ is no longer cut off at intervals, but the strand as it pushes against the baffle. 68 squeezes, thereby crumbling and regularly in small fragments falls into the firebox. In this mode of operation, it is possible to feed the fuel without operating it at intervals of the lifting motor 53 is to be left in operation until it is switched off by the filling switch 61. The slider 45 is only opened at the beginning of the fuel delivery and immediately closed again at the end of the delivery.

In this way, a conveyor system is created, which practically a continuous working and delivery of a approximately constant volume weight having fuel, in particular wood waste, ensures.

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Claims (17)

Claims 1) Conveyor system with a screw conveyor on the firing device, for solid fuel, in particular wood waste, that occurs with volume weights that change over time by a device for balancing the volume weight changes in solid fuel. 2) Conveyor system according to claim 1, characterized by one of the screw conveyor (1) downstream press member (24) and one Compression chamber (M), the outlet of which is closed with a force-loadable closure (5) in such a way that during operation the pressing member (1, 24) compresses the fuel in the chamber (4) until the fuel on the end (5) the force exerted opens it, and means (13) are provided are in order to close the chamber (4) again after the compressed fuel has been ejected. 3) conveyor system according to claim 2, characterized in that the closure is designed as a slide (5) which Has separating means in order to displace the compressed fuel material pushed out of the chamber (4), preferably transversely to its direction of movement, cut off in the area of the chamber exit, e.g. cut off. - 17 509810/0231 4) conveyor system according to claim 2, characterized in that the pressing member as a screw, in particular as a screw conveyor (1), or is designed as a piston (24), which or which the fuel in the press chamber in such a way compresses so that an air and fire retardant plug is created against backburn j whereby this fuel plug is present before the fuel reaches the furnace and the side of the plug facing the furnace (3) is continuously renewed during operation by the fuel supply, so that further security against fire burn-back bidding. 5) Conveyor system according to claim 2, characterized in that a further _{control element (19 s} 20, 21) actuated by the fuel level in the combustion chamber is provided in the pressing chamber (4) and the combustion chamber (3), which control element can switch off the conveyor system. 6) Conveyor system according to claim 2, characterized in that the closure formed as a slide (5) for the pressing chamber (4) can be loaded with a variable force (7, 25) and when this is exceeded. Force executes a pivoting movement. - 18 a
509810/0231 7) conveyor system according to claim 6, characterized in that the pivoting slide (5) directly or indirectly (17) a lifting device, e.g. a lifting motor (13), switches to move the slide (5) out of the range of motion of the Pulling away the pressing chamber of advancing fuel. 8) Conveyor system according to claim 7 _S, characterized in that after the slide (5) is pulled away from the area of the advancing fuel plug, it swivels back into its normal pivot position and the lifting motor (13) moves the slide (5) for the purpose of separating the fuel plug and closing the pressing chamber ( ^{Push 1} O in front of the bale chamber exit. 9) Conveyor system according to claim 2, characterized in that the pressing chamber (H) widens in the ejection direction, for example conically. 10) conveyor system according to claim 2 _S, characterized in that the closing slide (5) is spring-loaded (7) and / or weight-loaded (25). 11) conveyor system according to claim 2, characterized in that the closing member designed as a slide (5) - 19 509810/0231 Pressing chamber (4) has a cutting edge and the slide with the thrust motor (13) via a resilient member, for example, _s is connected to a spring member (15). 12) conveyor system according to claim 2, characterized in that when the conveyor system comes to a standstill, the press chamber (4) through a closing element (5) is closed on the discharge side. 13) conveyor system according to claims 1 and 2, characterized in that that the closure as a slide (5) and the pressing member as a screw, in particular as a conveyor screw (1), or is designed as a piston (24) which compresses the fuel in the press chamber in such a way that against Burnback creates an air and fire retardant plug, this fuel plug being present before the fuel gets into the furnace and the furnace (3) facing side of the plug during operation due to the fuel supply is continuously renewed and thus offers further security against fire burn-back, 14) Conveyor system according to claim 10, characterized in that the termination is in the form of a spring ring (69) with a jacket-shaped arrangement, resilient tongues is formed which protrude into the fuel delivery path and when conveying through the Fuel can be pressed outwards. - 20 - 509810/0231 15) Conveyor system according to claim 10, characterized in that the load on the slide, e.g. its pretension, is adjustable. 16) Conveyor system according to claim 1, characterized in that there is a deflection surface (68) in the fuel conveying path to dissolve the advancing fuel plug. 17) Conveyor system according to claim 1, characterized in that control means, e.g. a flap (60) are arranged, in order to turn off the screw conveyor (41) when a maximum value of the fuel level in the combustion chamber is exceeded and to lower the slide (45) and if one is exceeded The lowest value of the fuel level to lower the slide (45), to close the fuel outlet. 21 509810/0231 Blank page