FI3560865T3

FI3560865T3 - Discharge device for small sized bulk material and combustion device with such a discharge device

Info

Publication number: FI3560865T3
Application number: FIEP19171473.2T
Authority: FI
Inventors: Ernst Hutterer
Original assignee: Froeling Heizkessel Und Behaelterbau Ges M B H
Priority date: 2018-04-26
Filing date: 2019-04-26
Publication date: 2023-12-13
Also published as: EP3560865A1; SI3560865T1; EP3560865B1

Claims

The invention relates to a discharge device for small sized bulk material, more particularly for wood chips or pellets, having an inner part rotatable about a drive axis, having joint arms connected to the inner part via a joint in each case and can — be pivoted about an joint axis of the joint against a spring force into a folded position, and having a mechanical positive coupling acting between the two joint arms for synchronizing the pivoting movement of the joint arms, wherein the mechanical positive coupling has a lever arm linkage with a transmission element and with two actuating arms, wherein the actuating arms are movably connected both to the transmission element and also in each case at a distance from the joint with in each case one joint arm.

Forced mechanical coupling of joint arms of a discharge device in order to symmetricaliy empty a storage bunker of wood chips is known from the prior art.

For example, such a positive coupling is created in a discharge device to a wood chin — boiler USV of the company "”KWB - Kraft und Wärme aus Siomasse GmbH" published in 2004 by attaching a link chain to both joint arms, which thus couples them in motion.

This bottom agitator from KWB is also known as "KWB Fördersystem m" (KWB conveying system my), As an alternative to a link chain, EP 2585006 Bl proposes to realize a lever arm linkage with a rotatably mounted adjusting ring and two actuating arms pivotally linked thereto, which actuating arms are rotatably connected to the joint arms.

What ali these solutions have in common is the comparatively high design effort.

In addition, the mechanical positive couplings known from the prior art are comparatively susceptible to contamination - for exampig in the area of the link chain ortherotary joints - so that they can only be used in dusty environments to s limited extent or require correspondingly frequent maintenance.

The stability of such discharge devices for small sized bulk material is thus disadvantageous, The invention has therefore set itsel? the object of improving the stability of a discharge device of the type described at the beginning by simplifying the design in the mechanical positive coupling.

The invention solves the given object by the features of claim i.

If the transmission element has a rocker arm that can be tilted about the drive axis with two rocker arm sides, wherein the actuating arms are rotatably connected to the respective rocker arm side of the rocker arm and pivotably connected to the joint arms, a rotatable adjusting ring can be dispenssd with, which restricts the mobility of the actuating arms dus to the pivotable linkage.

Therefore, the discharge of the bulk material can be carried out safely even in an initial situation with very unevenly distributed bulk material - and, moreover, can lead to a faster equalization of the distribution of bulk materia! than is feasible with the prior art.

In addition, a rocker arm is comparatively simple to provide in the area of the inner part - it is also robust against contamination due to its rocker sides projecting from the rocker axis.

The design according to the invention can therefore De used to ensure particularly high stability in the discharge of small size bulk materials.

Preferably, the two rocker arm sides extend away from the drive axis, as can be seen in Fig. 1.

The design of the discharge device is further simplified because the rocker arm is tiltably mounted on the drive shaft with the drive axis for rotating the inner part via a tilting bearing.

The rocker arm is thus directly mounted on the drive shaft or supported on the drive shaft.

It is possible to ensure equal loads on the joint arms if the two rocker arm sides of the rocker arm are of equal length - which means that no transmission in the force coupling is to be expected, Preferably, the rocker arm sides are straight.

If the rocker arm is engaged by at least one spring which generates the spring force against which the joint arms can be pivoted into the foided position, a central point forthe introduction of the spring force can be found in an elegant manner.

In addition, this point of application is comparatively easy to protect against function-endangering contamination.

The stability of the discharge device can thus be further increased.

A helical tension spring can particularly be used as a spring.

Advantageous conditions for discharging bulk material result if the spring has a linear

— spring characteristic.

Symmetrical loads on the rocker arm can be ensured if a spring acts on each of the two rocker arm sides, the spring forces of which act in opposite directions on the rocker arm.

In addition, this double-sided spring loading of the rocker arm can make the adjustment of the spring force acting on the joint arms comparable.

The design of the fever arm linkage can be simpiified if the actuating arms extend in a straight manner.

The range of the joint arms can be increased if the joint arms each have an inner arm part and an outer arm part pivotably articulated thereto.

The outer arm part can bs coupled to the movement of the inner arm part - in a simple design - if a flexible traction element engages in each case on an actuating arm and on an outer arm part.

A rope, beit or, more particularly, a link chain is suitable as a flexible traction element, for example, to withstand contamination with dirt.

If the flexible tensile element is defiscted at the Inner arm part, for which the inner arm part has a deflection device, it is possible to keep its extension within the range of the joint arms.

This reduces the risk of contamination of the flexible traction slement and thus increases its stability.

For this purpose, the deflection device can, for example, comprise a roller, a pin, a gearwheel, etc.

If the first internal angle & between the rocker arm and the respective actuating arm increases from the folded position of the joint arms to the unfolded position of the joint arms, advantageous force application to the joint arms can be enabled.

More particularly, if the first internal angle « changes from acute to obtuse in the process.

The smaller angle more particularly acute, angle results in a low force application to the joint arms, which only increases as the angle increases, This means that the high force on the joint arms at the beginning of the discharge of bulk material, which is known from conventional systems, can be avoided - which reduces frictional forces and thus reduces wear on the discharge device.

In addition, this means that the discharge according to the invention requires a reduced input of energy.

If the joint arms move away from the folded-together position, their force load on bulk material — etc, also increases, which can ensure its discharge particularly well,

This aforementioned application of force to the joint arms can be increased by the lever mechanism according to the invention if the second internal angle B between the respective actuating arm and the joint arm adjoining it is reduced from the folded- together position of the joint arms to the unfoided position of the joint arms. More particularly, if the second internal angle § changes from obtuss to acute in the Process, A high degree of reinforcement can be achieved if the actuating arms are pivotaiiy connected to the respective joint arms in the first half, as seen from the relevant joint. More particularly, the discharge device according to the invention can be suitable for feeding a combustion device with bulk material as combustion material, For example, wood chips, pellets and/or other wood-based materials can serve as combustion material, In the figures the subject matter of the invention is shown in more detail by way of example on the basis of an embodiment variant, wherein

Fig. 1 shows a top view of a discharge device with unfolded joint arms,

Fig. 2 shows a top view of the discharge device shown in Fig, 1 with folded joint arms, and

Fig. 3 shows a superimposed view of the positive coupling in different positions of the joint arms. According to Fig. 1, for example, a discharge device 1 for a small sized bulk material not shown, for example for wood chips, pellets, etc., is shown, Such a discharge device 1 can serve, for example, for feeding a combustion plant. The discharge device i has an inner part 2 which is rotatable about a drive axis A of a drive shaft 13 of an — electric drive or transmission which is not shown. Two joint arms 3, 4 are articulated to the inner part 2 - namely, these are connected to the inner part 2 via a joint 5, 6 in each case. Thus, these joint arms 3, 4 can each be pivoted about the joint axis G of the respective joint 5, 6 against a spring force F from an unfoided position 7.1 shown in

Fig. 1 to a folded position 7.2 shown in Fig, 2.

A uniform discharge of wood chips, etc, is ensured by a mechanical positive coupling 8, which synchronizes the pivoting movement of the joint arms 3, 4 relative to the inner part 2. The mechanical positive coupling 8 is achieved with a lever arm linkage 9, which has a transmission element 9.1 and two actuating arms 9.2, 9.3. These two 5 actuating arms 9.2, 9.3 are movably connected to the transmission element 9.1. Each actuating arm 9.2, 9.3 is movably connected fo ons of the joint arms 3, 4 - namely at a bearing point, spaced from the joint 5, 6 of the respective joint arm 3, 4. Moreover, the actuating arms 9.2, 9.3 extending in a straight manner, which in turn facilitates maintenance, assembly, etc, of the discharge device 1. According to the invention, the transmission element 9.1 now has a rocker arm 10 which can be tilted about the drive axis A, thus achieving a high degree of mechanical stability. According to Fig. 1, this rocker arm 10 can be seen particularly well, Thus, it can be seen that the two-armed rocker arm 10 has two straight rocker arm sides

10.1, 10.
2. The rocker arm sides 10.1, 10.2 have a bearing bore 10.3 on the rocker arm 10 between them, as can also be seen in Fig. 3. Thus, the two rocker arm sides

10.1, 10.2 extend away from the tiitabie bearing of the rocker arm 10 and thus also away from the drive axis A, as can be seen in Fig. 1. The actuating arms 8.2, 9.3 are each connected to this rocker arm 10 so as to be rotatable about an axis of rotation D of a rotary joint 11, namely at the ends of the — respective rocker arm sides 10.1, 10.2 of the rocker arm 10. At the other end, the actuating arms 9.2, 9.3 are connected to the respective joint arms 3, 4 so that they can pivot about a pivot axis S of s pivot joint 12, The axes of rotation D and pivot axes S extend parallel to the drive axis A, These factors result in simplified design conditions which are resistant to contamination. This advantage is particularly pronounced in that the rocker arm 10 is tiitabiy mounted on the drive shaft 13 with the drive axis A for rotating the inner part 2, as can be recognized in Fig, 1. Between the drive shaft 13 and the rocker arm 10 there is a rocker bearing K, which is formed by a plain bearing, for example, One bearing part of the tilting bearing K is fastened to the bearing bore 10.3 of the rocker arm 10 -the other bearing part is fastened to the drive shaft 13. In addition, the two rocker arm sides 10.1,10.2 of the rocker arm 10 are formed with the same length to ensure a transmission-free coupling between the joint arms 3, 4 for uniform discharge, The spring loading on the joint arms 3, 4 is due to two springs 14.1, 14.2 - namely helical tension springs in the exemplary embodiment - which act on the rocker arm 2120 and thus load it with the spring forces Fi, F2, against which the joint arms 3, 4 can bs pivoted into the folded position 7.2. For this purpose, the two springs 14.4,

14.2 act on both rocker arm sides 10.1, 10.2, with the springs 14.1, 14.2 acting in opposite directions on the rocker arm 10 and thus complementing each other in terms of their spring force, Alternatively, a compression spring can also be used, which is not shown. The range of the joint arms 3, 4 is increased by their two-part design, For this purpose, each joint arm 3, 4 has an inner arm part 3.1, 4.1 and an outer arm part
3.2, 4.2 that is articulated to the inner arm part. A flexible traction element 15.1, 15,2, namely a link chain, is attached in each case to one actuating arm 9.2, 9.3 and one outer arm part 3.2, 4.2. For this purpose, there are attachment points 16 on the actuating arms 9.2, 8.3 and on the outer arm parts 3.2, 4.2, via which the respective traction element can also be tensioned. The outer arm part 3.2,4.2 is thus coupled to the respective inner arm part 3.1,4.1 in movement, which means that this part of the joint arm 3, 4 can also be pivoted into a folded position 7.2 against the spring force FL, F2. The fiexible traction element 15.1, 15.2 is guided in the area of the respective joint arm 3, 4. This is carried out using a deflaction device 17.1, 17.2 on the inner arm part 3.1, 4.1, which deflection device 17.1, 17.2 is designed as a roller. The flexible traction element 15.1, 15.2 is thus guided in such a way that it is protected against contamination - which increases the stability of the discharge device i. According to Fig. 3, different angular positions of the positive coupling 8 are shown superimposed. Thus, both end positions, namely the unfolded position 7.1 and the folded position 7.2 of the joint arm 3 are shown, as well as the middie position 7.3 of the joint arm 3. As can be seen from Fig, 3 - representative of both joint arms 3, 4 - the first internal angle « between the rocker arm 10 and the actuating arm 9.2 changes from acute in the folded position 7.2 of the joint arm 3 to obtuse in the unfolded position 7.1 of the joint arm 3. By applying a near spring force of a helical tension spring to the rocker arm 10, which is more stretched in the collapsed position 7.2 than in the unfolded — position 7.1, a force transmission can thus be created which exerts a reduced force on the joint arms 3, 4 in the collapsed position 7,2. The acute angle results in a low transmission of the spring force Fl to the joint arms 3, 4, which transmission increases to a maximum as the first internal angle & increases. However, since the spring force FL of spring 14.2 also decreases with further opening of the joint arms 3, 4, this leads to a decreasing force on the joint arms 3, 4 after the maximum. A Gaussian-curve-shaped force load is thus formed on the joint arms 3, 4, which ensures the discharge of bulk material in an energy-saving manner. An amplification of the Gaussian-curve-shaped force load is achieved Dy the lever arm linkage 9, in that the second internat angle 8 between the respective actuating arm 9.2, 9.3 and the joint arms 3, 4 adjoining it changes from obtuse in the folded position 7.2 of the joint arms 3, 4 to acute in the unfoided position 7.1 of the joint arms 3, 4, which can be seen in Fig. 3. A high degree of amplification is set by pivotally connecting the actuating arms 9.2,

9.3 to the respective joint arms 3, 4 - as seen from the respective joint 5, 6 - in the first half,