EP4056900B1 - Biomass heating system with an improved cleaning device - Google Patents

Description

TECHNICAL AREA

The invention relates to a biomass heating system and its components. In particular, the invention relates to a biomass heating system with an improved cleaning device.

STATE OF THE ART

Biomass heating systems, in particular biomass boilers, in a power range from 20 to 500 kW are known. Biomass can be considered a cheap, domestic, crisis-proof and environmentally friendly fuel. There are, for example, wood chips or pellets as combustible biomass or biogenic solid fuels.

The pellets usually consist of wood shavings, sawdust, biomass or other material that has been compacted into small discs or cylinders approximately 3 to 15 mm in diameter and 5 to 30 mm long. Wood chips (also known as wood chips, woodchips or woodchips) are wood that has been crushed with cutting tools.

Biomass heating systems for fuels in the form of pellets and wood chips essentially have a boiler with a combustion chamber (the combustion chamber) and a heat exchange device connected to it. Due to the stricter legal regulations in many countries, some biomass heating systems also have a fine dust filter. Other various accessories are regularly available, such as fuel delivery devices, control devices, probes, safety thermostats, pressure switches, exhaust gas recirculation, boiler cleaning and a separate fuel container.

A device for supplying fuel, a device for supplying air and an ignition device for the fuel are regularly provided in the combustion chamber. In turn, the means for supplying the air normally comprises a low-pressure fan in order to favorably influence the thermodynamic factors of combustion in the combustion chamber. A device for supplying fuel can be provided, for example, with a lateral insert (so-called transverse insert firing). The fuel is pushed into the combustion chamber from the side via a screw or a piston.

In the combustion chamber of a fixed-bed furnace, a furnace grate is also usually provided, on which the fuel is essentially supplied and burned continuously. This grate stores the fuel for combustion and has openings, for example slots, which allow the passage of part of the combustion air as primary air to the fuel. Next, the grate can be rigid or movable. There are also grate furnaces in which the combustion air is not fed through the grate but only from the side.

When the primary air flows through the grate, the grate is also cooled, which protects the material. In addition, if there is insufficient air supply, slag can form on the grate, whereby the slag can also be detached (e.g. when cleaning the grate) and carried further into the rest of the biomass heating system. In particular furnaces that are to be charged with different fuels, with which the present disclosure is particularly concerned, have the inherent problem that the different fuels have different ash melting points, water contents and different combustion behavior and thus variable combustion residues. It is therefore problematic to provide a heating system that is equally well suited for different fuels. Good suitability for different fuels requires regular and efficient cleaning of the biomass heating system.

The combustion chamber can also be regularly divided into a primary combustion zone (immediate combustion of the fuel on the grate and in the gas space above it before additional combustion air is supplied) and a secondary combustion zone (post-combustion zone of the flue gas after additional air supply). Drying, pyrolytic decomposition, gasification of the fuel and charcoal combustion take place in the combustion chamber. In order to completely burn the resulting combustible gases, additional combustion air is introduced in one or more stages (secondary air or tertiary air) at the start of the secondary combustion zone.

After drying, the combustion of the pellets or wood chips essentially has two phases. In the first phase, the fuel is at least partially pyrolytically decomposed and converted into gas by high temperatures and air that can be blown into the combustion chamber. In the second phase, the (partial) part that has been converted into gas is burned, as well as the burning of any remaining solids (e.g. charcoal). In this respect, the fuel outgasses, and the resulting gas and the charcoal contained therein are also burned.

Pyrolysis is the thermal decomposition of a solid substance in the absence of oxygen. Pyrolysis can be divided into primary and secondary pyrolysis. The products of primary pyrolysis are pyrolysis coke and pyrolysis gases, the pyrolysis gases being divided into room temperature condensable and non-condensable gases. The primary pyrolysis takes place at roughly 250-450°C and the secondary pyrolysis at around 450-600°C. The secondary pyrolysis that subsequently occurs is based on the further reaction of the pyrolysis products that were primarily formed. The drying and pyrolysis take place at least largely without the use of air, since volatile CH compounds escape from the particle and therefore no air can reach the particle surface. Gasification can be seen as part of oxidation; the solid, liquid and gaseous products formed during the pyrolytic decomposition are reacted by further exposure to heat. This is done with the addition of a gassing agent such as air, oxygen, water vapor or carbon dioxide. The lambda value during gasification is greater than zero and less than one. Gasification takes place at around 300 to 850°C or even up to 1,200°C. The complete oxidation with excess air (lambda greater than 1) takes place by adding more air to these processes. The end products of the reaction are essentially carbon dioxide, water vapor and ash. In all phases, the boundaries are not rigid, but fluid. The combustion process can be advantageously regulated by means of a lambda probe provided at the exhaust gas outlet of the boiler.

Generally speaking, converting the pellets into gas increases combustion efficiency because gaseous fuel is better mixed with the combustion air and thus more completely converted, and lower emissions of pollutants, unburned particles and ash (fly ash or dust particles) are produced .

The combustion of biomass produces gaseous or airborne combustion products, the main components of which are carbon, hydrogen and oxygen. These can be divided into emissions from complete oxidation, from incomplete oxidation and substances from trace elements or impurities. The emissions from complete oxidation are essentially carbon dioxide (CO ₂ ) and water vapor (H ₂ O). The formation of carbon dioxide from the carbon in the biomass is the goal of combustion, as the released energy can be used more fully. The release of carbon dioxide (CO ₂ ) is largely proportional to the carbon content of the fuel burned; thus the carbon dioxide is also dependent on the useful energy to be provided. A reduction can essentially only be achieved by improving the efficiency. The boiler further usually has a radiant part, which is integrated into the combustion chamber, and a convection part (the heat exchanger connected thereto).

The exhaust gas from the combustion in the combustion chamber is fed to the heat exchanger so that the hot combustion gases flow through the heat exchanger in order to To transfer heat to a heat exchange medium, which is typically water at about 80°C (usually between 70°C and 110°C). During this cooling process in particular, combustion residues can get stuck in the pipes of the heat exchanger and also adhere very firmly.

The complex combustion processes described above are not easy to control. Different types of fuel residues, such as ash or slag, can arise, which spread throughout the course of the flow of the biomass heating system and which can be cleaned off with varying degrees of ease.

In particular, these combustion residues can stick to the walls or other parts of the boiler, depending on the temperature condition or also, for example, in the event of condensation and also in an (optional) electrostatic precipitator. A particular problem is that the adhesion of the combustion residues can be very strong or permanent, which means that cleaning the boiler (especially when cleaning it by hand) is quite difficult. Practice shows that the combustion residues can stick or cake, especially in the heat exchanger and in the (optional) electrostatic precipitator, which makes cleaning them even more difficult.

In particular furnaces that are to be charged with different fuels, with which the present disclosure is particularly concerned, have the inherent problem that the different fuels have different ash melting points, water contents and different combustion behavior. In particular, heating systems with fuel-flexible charging have the problem of very variable - in practice hardly predictable - formation of combustion residues with different chemical and physical properties. In this respect, cleaning of the biomass heating system must also be able to cope with these different combustion residues.

In principle, the other problems with conventional biomass heating systems are that the gaseous or solid emissions are too high, that the efficiency is too low and that the dust emissions are too high. Another problem is the varying quality of the fuel, due to the varying water content and the lumpiness of the fuel, which makes it difficult to burn the fuel evenly with low emissions. In particular in the case of biomass heating systems, which are intended to be suitable for different types of biological or biogenic fuel, the varying quality and consistency of the fuel makes it difficult to maintain consistently high efficiency of the biomass heating system. There is a need for optimization in this regard.

A disadvantage of traditional pellet biomass heating systems can be that pellets falling into the combustion chamber can roll off the grid or grate, slide off, or land next to the grate and end up in an area of the combustion chamber where the temperature is lower or where the air supply is poor, or they can even fall into the bottom chamber of the boiler or the ash chute. Pellets that are not left on the grid or grate burn incompletely, causing poor efficiency, excessive ash and a certain amount of unburned pollutant particles, which in turn pollute the biomass heating system. This applies to pellets as well as wood chips.

The state of the art DE 10 94 912 B discloses a device for cleaning the flue gas side of the flue pipes of stationary heating boilers, in which helical guide elements that can be raised and lowered are arranged in the flue pipes, characterized in that the drive device for the reciprocating movement of the helical guide elements 2 is designed in such a way that in each case at the end of the reciprocating movements jerky impacts on these guide elements and possibly triggered simultaneously on the tubes 1.

The state of the art U.S. 2,233,066 A discloses in claim 1 the following: In a heat exchanger, a plurality of elements, the passages for with define contaminant-laden gas, means for removing accumulated deposits from the elements, which include flexible chains disposed in the passageways, rods from which a plurality of the chains are each suspended, and a shaft having rocker arms supporting the rods, the arrangement being such that as the arms are tilted the chains are moved up and down and side to side to contact the elements with a sweeping motion to clear any accumulated debris.

As further prior art relating to a cleaning device for a boiler is the EP 1 830 130 A2 known. This discloses a heating boiler with a flue gas flap for essentially smoke-free opening of a filling door of a filling space. To fill the boiler with fuel, it is proposed to equip the filling door with a safety device which, when the filling door is open or closed and the flue gas flap is open and locked, generates a signal and possibly displays it or releases the locking of the open flue gas flap when the filling door is closed or while the filling door is being closed. The safety device is in particular a spring-loaded rocker arm, which serves as a sensor for an open or closed filling door and as a switching element for actuating an actuating lever for the flue gas flap. The actuating lever can optionally also actuate a heat exchanger cleaning device at the same time, which is coupled to the flue gas damper.

This cleaning device has the disadvantages that it has to be operated manually and that the movement of the heat exchanger cleaning device by operating the operating lever results in an inefficient mechanical cleaning process which has problems in removing the combustion residues from the heat exchanger.

Biomass heating systems for pellets or wood chips with cleaning devices of the prior art have the following further disadvantages and problems.

The volume of the cleaning process is often quite considerable, which is undesirable, for example, in the case of biomass heating systems for residential buildings.

The cleaning is inefficient and requires the cleaning process to be carried out frequently and/or over a longer period of time in order to achieve an adequate cleaning effect.

The cleaning is incomplete. Combustion residues remain in the biomass heating system. This applies in particular to the gas-carrying parts of the system, which are not directly touched or caught by the mechanical cleaning.

The cleaning devices are mechanically complex. For example, these require a number of different drives and mechanisms provided separately from one another for cleaning the different parts of the system. For example, electrostatic precipitators and heat exchangers are usually cleaned using different mechanisms.

Interruptions in the operation of the biomass heating system in order to carry out maintenance work for cleaning, which must be carried out due to the inefficiency and incompleteness of the prior art automatic cleaning devices, are also disruptive. In order to reduce the combustion residues and thus increase the maintenance interval, a large excess of air is normally disadvantageously maintained in the combustion chamber, but this reduces the flame temperature and the efficiency of the combustion, and there are increased emissions of unburned gases (e.g. CO, CyHy) , NOx and dust (e.g. due to increased turbulence). This is also a problem that conventional biomass heating systems with cleaning devices can have.

Furthermore, there is also a need for optimization, in particular in the case of the heat exchangers of biomass heating systems of the prior art, ie their efficiency could be increased. The efficiency of the heat exchanger is also dependent on it depending on the degree of pollution. There is therefore a need for improvement with regard to the often cumbersome and inefficient cleaning of conventional heat exchangers.

The same applies to the usual electrostatic precipitators of biomass heating systems. Their spray and separating electrodes are regularly clogged with combustion residues, which impairs the formation of the electric field for filtering and reduces the efficiency of the filtering.

It is consequently an object of the invention to provide a biomass heating system with an optimized cleaning device.

As a result, it can also be an object of the invention to provide a biomass heating system in hybrid technology, which is low in emissions (especially with regard to fine dust, CO, hydrocarbons, NOx), which can be operated flexibly with wood chips and pellets, and which has a high has efficiency. The above may be the secondary consequence of improved cleaning.

• Die Hybridtechnologie soll sowohl den Einsatz von Pellets als auch von Hackgut mit Wassergehalten zwischen 8 und 35 Gewichtsprozent ermöglichen.
• Möglichst niedrige gasförmige Emissionen (kleiner als 50 oder 100 mg/Nm³ bezogen auf trockenes Rauchgas und 13 Volumenprozent O₂) sollen erzielt werden.
• Sehr niedrige Staubemissionen kleiner 15 mg/Nm³ ohne und kleiner 5 mg/Nm³ mit Elektrofilterbetrieb werden angestrebt.
• Ein hoher Wirkungsgrad von bis zu 98% (bezogen auf die zugeführte Brennstoffenergie (Heizwert) soll erreicht werden.

According to the invention and in addition, the following considerations can play a role:

• The hybrid technology should enable the use of both pellets and wood chips with a water content of between 8 and 35 percent by weight.
• Gaseous emissions that are as low as possible (less than 50 or 100 mg/Nm ³ based on dry flue gas and 13 percent by volume O ₂ ) should be achieved.
• Very low dust emissions of less than 15 mg/Nm ³ without and less than 5 mg/Nm ³ with electrostatic precipitator operation are aimed for.
• A high degree of efficiency of up to 98% (based on the fuel energy supplied (calorific value) should be achieved.

Furthermore, one can take into account that the operation of the system should be optimized. For example, simple ash removal, simple cleaning or simple maintenance should be made possible.

In addition, there should be high plant availability.

The task mentioned above or the potential individual problems can also relate to individual partial aspects of the overall system, for example to the combustion chamber, the heat exchanger or the electrical filter device.

This object(s) is/are solved by the subject matter of the independent claim. Further aspects and advantageous developments are the subject matter of the dependent claims.

According to one aspect of the present invention, a biomass heating system for firing fuel in the form of pellets and/or wood chips is provided, the biomass heating system having the following:
a boiler with a burner, a heat exchanger with a plurality of boiler tubes, a cleaning device, which has the following: a drive unit for driving the cleaning device, a crank element which is coupled to the drive unit via a freewheel, the drive unit rotating the crank element in one direction can drive, a pushing member which is reciprocably provided and which is coupled to the crank member; at least one cleaning shaft operatively coupled to the thrust member, at least one cleaning element disposed operatively connected to the cleaning shaft; wherein the cleaning device is set up in such a way that when the crank element rotates in the direction of rotation, the thrust member is displaced in a thrust direction by the drive unit; and after a predetermined crank rotational position of the crank element has been exceeded, the thrust member is displaced in an impulse direction which is opposite to the thrust direction.

According to a development of the above, a biomass heating system is provided, with the cleaning device (9) being set up in such a way that the movement of the thrust member in the direction of the impulse is not effected by the drive unit.

According to a development of the above, a biomass heating system is provided, with the cleaning device (9) being set up in such a way that the movement of the thrust member in the direction of the impulse is caused by a torque of the cleaning shaft.

According to a development of the above, a biomass heating system is provided, wherein the at least one cleaning element is raised by the rotation of the crank element until the predetermined crank rotary position is reached, and the at least one cleaning element is accelerated after the predetermined crank rotary position has been exceeded due to the weight of the at least one cleaning element o or falls suddenly.

According to a further development of the above, a biomass heating system is provided, with the cleaning device being set up in such a way that the movement of the pushing member in the pushing direction takes place at least approximately uniformly.

According to a further development of the above, a biomass heating system is provided, with the cleaning device being set up in such a way that the movement of the thrust member is accelerated in the pulse direction.

Biomass heating system according to one of the preceding claims, wherein the thrust member has an opening for a crank extension of the crank element.

According to a development of the above, a biomass heating system is provided, wherein the thrust member has at least one elongate guide hole for receiving at least one guide pin for movably guiding the thrust member.

According to a development of the above, a biomass heating system is provided, wherein the thrust member is arranged to be movable back and forth in a straight line.

According to a development of the above, a biomass heating system is provided, wherein the at least one cleaning shaft has a lever with a lever pin on an end of the lever that is distal in relation to the cleaning shaft; and the thrust member has at least one elongated fulcrum pin hole for movably receiving the fulcrum pin.

According to a development of the above, a biomass heating system is provided, wherein the at least one cleaning element is at least one turbulator, preferably a spiral turbulator and/or a belt turbulator, which is/are provided in at least one boiler tube of the heat exchanger.

According to a development of the above, a biomass heating system is provided, the cleaning device being set up in such a way that the freewheel transmits the torque of the motor in the direction of rotation of the crank element; and the freewheel releases further rotation of the crank element in the direction of rotation when the predetermined crank rotational position of the crank element is exceeded.

According to a further development of the above, a biomass heating system is provided, with the thrust member having a stop as an end stop for the movement in the pulse direction.

According to a further development of the above, a biomass heating system is provided, with an opening in the thrust member being provided for receiving a roller of the crank extension.

In this case, the opening can have a diameter in one direction of the opening which corresponds approximately to the crank radius plus the radius of the roller (or the crank extension); and it can open in a different direction that perpendicular to the one direction, have a diameter less than about the crank radius plus the radius of the pulley (or crank extension).

According to a development of the above, a biomass heating system is provided, with the opening of the thrust member having a step that is exceeded by the roller when the predetermined crank rotational position is reached.

According to a development of the above, a biomass heating system is provided, this further comprising: a damping element, preferably a spring, which is arranged such that the damping element dampens the movement of the thrust member in the direction of thrust.

According to a development of the above, a biomass heating system is provided, wherein: a contraction and expansion direction of the damping element is provided at least approximately parallel to the direction of the back and forth movement of the damping element.

According to a further development of the above, a biomass heating system is provided, with the thrust member being provided in the form of a plate and/or with one end of the at least one cleaning shaft serving as a guide pin for receiving in an elongate guide hole.

According to a development of the above, a biomass heating system is provided, this further comprising: an electrostatic filter device with a spray electrode and a cleaning cage as a counter-electrode, the cleaning element being an impact lever; and wherein the impact lever is operatively connected to the cleaning shaft and is arranged in such a way that the impact lever strikes the discharge electrode for cleaning when the cleaning shaft rotates abruptly.

According to a development of the above, a biomass heating system is provided, with a sensor, for example an inductive position switch, being provided for detecting the position or the end position of the thrust member.

According to a development of the above, a biomass heating system is provided, with an ash discharge screw of the biomass heating system also being driven by the drive unit.

The structural features, functions and advantages of the above aspects are described in more detail in the following description with the aid of exemplary embodiments.

The following aspects of the present disclosure can be combined with the preceding ones as desired. In this way, the biomass heating system can be further improved in synergy with the optimized cleaning device.

According to a further general aspect of the present disclosure, a biomass heating system for firing fuel in the form of pellets and/or wood chips is disclosed, the system comprising the following: a boiler with a burner, a heat exchanger with a plurality of boiler tubes, the burner comprising: a combustion chamber having a rotary grate, having a primary combustion zone and having a secondary combustion zone; the primary combustion zone being encompassed by a plurality of combustion chamber bricks laterally and by the rotary grate from below; a plurality of secondary air nozzles being provided in the combustor bricks; the primary combustion zone and the secondary combustion zone being separated at the level of the secondary air nozzles; wherein the secondary combustion zone of the combustor is fluidly connected to an inlet of the heat exchanger.

According to a development of the above, a biomass heating system is provided, with the secondary air nozzles being arranged in such a way that in the secondary combustion zone of the combustion chamber, turbulent flows of a flue gas-air Mixture of secondary air and combustion air arise around a vertical central axis, with the eddy currents leading to an improvement in the mixing of the flue gas-air mixture.

According to one development, a biomass heating system is provided, with the secondary air nozzles in the combustion chamber bricks each being designed as a cylindrical or truncated cone-shaped opening in the combustion chamber bricks with a circular or elliptical cross section, the smallest diameter of the respective opening being smaller than its maximum length.

According to one development, a biomass heating system is provided, the combustion device with the combustion chamber being set up in such a way that the turbulent flows form spiral-shaped rotational flows after exiting the combustion chamber nozzle, which reach up to a combustion chamber ceiling of the combustion chamber.

According to a development, a biomass heating system is provided, with the secondary air nozzles being arranged at least approximately at the same height in the combustion chamber; and the secondary air nozzles are arranged with their central axis and/or (depending on the type of nozzle) aligned in such a way that the secondary air is introduced acentrically to a center of symmetry of the combustion chamber.

According to a development, a biomass heating system is provided, with the number of secondary air nozzles being between 8 and 14; and/or the secondary air nozzles have a minimum length of at least 50 mm with an inner diameter of 20 to 35 mm.

According to a further development, a biomass heating system is provided
the combustion chamber in the secondary combustion zone has a combustion chamber slope which reduces the cross section of the secondary combustion zone in the direction of the inlet of the heat exchanger.

According to a development, a biomass heating system is provided, wherein the combustion chamber in the secondary combustion zone has a combustion chamber cover which is provided inclined upwards in the direction of the inlet of the heat exchanger and which reduces the cross section of the combustion chamber in the direction of the inlet.

According to a development, a biomass heating system is provided, with the combustion chamber slope and the inclined combustion chamber ceiling forming a funnel, the smaller end of which opens into the inlet of the heat exchanger.

According to a development, a biomass heating system is provided, with the primary combustion zone and at least part of the secondary combustion zone having an oval horizontal cross section; and/or the secondary air nozzles are arranged in such a way that they introduce the secondary air tangentially into the combustion chamber.

According to a development, a biomass heating system is provided, with the average flow speed of the secondary air in the secondary air nozzles being at least 8 m/s, preferably at least 10 m/s.

According to a development, a biomass heating system is provided, with the combustion chamber bricks having a modular structure; and any two semi-circular combustor bricks form a closed ring to form the primary combustion zone and/or part of the secondary combustion zone; and at least two rings of bricks are stacked one on top of the other.

According to a development, a biomass heating system is provided, with the heat exchanger having spiral turbulators arranged in the boiler tubes, which extend over the entire length of the boiler tubes; and the heat exchanger includes strip turbulators located in the boiler tubes and extending at least half the length of the boiler tubes.

According to a further aspect of the present disclosure, a biomass heating system for firing fuel in the form of pellets and/or wood chips is provided, which has the following: a boiler with a combustion device, a heat exchanger with a plurality of boiler tubes, preferably arranged in a bundle-like manner, the combustor comprising: a combustor having a rotary grate and having a primary combustion zone and a secondary combustion zone, preferably provided above the primary combustion zone; the primary combustion zone being encompassed by a plurality of combustion chamber bricks laterally and by the rotary grate from below; wherein secondary combustion zone includes a combustor nozzle or burn-through hole; wherein the secondary combustion zone of the combustor is fluidly connected to an inlet of the heat exchanger; wherein the primary combustion zone has an oval horizontal cross-section.

In the case of boiler tubes arranged in a bundle-like manner, there can be a plurality of boiler tubes which are arranged parallel to one another and have at least largely the same length. Preferably, the inlet openings and the outlet openings of all boiler tubes can each be arranged in a common plane; i.e. i.e. the inlet openings and the outlet openings of all boiler tubes are at the same level.

In the present case, "horizontal" can denote a level orientation of an axis or a cross section, assuming that the boiler is also set up horizontally, with which, for example, the ground level can be the reference. Alternatively, "horizontal" as used herein means "parallel" to the base plane of vessel 11 as commonly defined. Further alternatively, in particular if there is no reference plane, "horizontal" can be understood merely as "parallel" to the combustion plane of the grate.

Furthermore, the primary combustion zone can have an oval cross-section.

The oval horizontal cross-section has no dead corners, and thus has improved air flow and the possibility of largely unhindered vortex flow up. Consequently, the biomass heating system has improved efficiency and lower emissions. In addition, the oval cross-section is well adapted to the type of fuel distribution when it is fed in from the side and the resulting geometry of the fuel bed on the grate. An ideally "round" cross section is also possible, but not so well adapted to the geometry of the fuel distribution and also to the flow technology of the turbulent flow, with the asymmetry of the oval compared to the "ideally" circular cross-sectional shape of the combustion chamber improving the formation of a turbulent flow in the combustion chamber allows.

According to a development, a biomass heating system is provided, with the horizontal cross-section of the primary combustion zone being provided at least approximately the same over a height of at least 100 mm. This also serves to ensure the unhindered development of the flow profiles in the combustion chamber.

According to a development, a biomass heating system is provided, with the combustion chamber in the secondary combustion zone having a combustion chamber slope which narrows the cross section of the secondary combustion zone in the direction of the inlet or inlet of the heat exchanger.

According to one development, a biomass heating system is provided, with the rotary grate having a first rotary grate element, a second rotary grate element and a third rotary grate element, each of which rotates about a horizontally arranged bearing axis by at least 90 degrees, preferably at least 160 degrees, even more preferably by at least 170 degrees , are rotatably arranged; wherein the rotary grate elements form a combustion surface for the fuel; wherein the rotary grate elements have openings for the air for combustion, wherein the first rotary grate element and the third rotary grate element are identical in their combustion surface.

The openings in the rotary grate elements are preferably designed in the form of slots and in a regular pattern in order to ensure a uniform flow of air through the fuel bed.

According to a further development, a biomass heating system is provided, with the second rotary grate element being arranged in a form-fitting manner between the first rotary grate element and the third rotary grate element and having grate lips which are arranged in such a way that, when all three rotary grate elements are in the horizontal position, they at least largely form a seal on the first rotary grate element and the third rotary grate element.

According to one development, a biomass heating system is provided, with the rotary grate also having a rotary grate mechanism that is configured in such a way that it can rotate the third rotary grate element independently of the first rotary grate element and the second rotary grate element, and that this rotates the first rotary grate element and the second rotary grate element together but can rotate independently of the third rotary grate element.

According to a development, a biomass heating system is provided, with the combustion surface of the rotary grate elements being configured as an essentially oval or elliptical combustion surface.

According to a development, a biomass heating system is provided, wherein the rotary grate elements have mutually complementary and curved sides, the second rotary grate element preferably having concave sides in each case towards the adjacent first and third rotary grate element, and preferably the first and third rotary grate element each towards the second rotary grate element have a convex side.

According to a development, a biomass heating system is provided, with the combustion chamber bricks having a modular structure; and every two semi-circular combustor bricks form a closed ring to form the primary combustion zone; and at least two rings of bricks are stacked one on top of the other.

According to a further development, a biomass heating system is provided, the heat exchanger having spiral turbulators arranged in the boiler tubes extend along the entire length of the boiler tubes; and the heat exchanger includes strip turbulators located in the boiler tubes and extending at least half the length of the boiler tubes. The band turbulators can preferably be arranged in or inside the spiral turbulators. In particular, the band turbulators can be integrated into the spiral turbulators. The band turbulators can preferably extend over a length of 30 to 70% of the length of the spiral turbulators.

According to a development, a biomass heating system is provided, with the heat exchanger having between 18 and 24 boiler tubes, each with a diameter of 70 to 85 mm and a wall thickness of 3 to 4 mm.

According to a development, a biomass heating system is provided, the boiler having an integrated electrostatic filter device, which has a spray electrode and a precipitation electrode surrounding the spray electrode and a cage or a cage-like cleaning device; wherein the boiler further comprises a mechanically operable cleaning device with a hammer lever with a stop head; wherein the cleaning device is set up in such a way that it can hit the end of the (spray) electrode with the stop head, so that a shock wave is generated by the electrode and/or a transverse vibration of the (spray) electrode in order to remove impurities from the electrode to clean up. A steel is provided as the material for the electrode, which can be caused to oscillate (longitudinally and/or transversely and/or shock wave) by the stop head. Spring steel and/or chromium steel, for example, can be used for this purpose. The material of the spring steel can preferably be an austenitic chromium-nickel steel, for example 1.4310. Next, the spring steel can be cambered. The cage-shaped cleaning device can be further moved back and forth along the wall of the electrostatic filter device for cleaning the collecting electrode.

According to a further development, a biomass heating system is provided, with a cleaning device integrated into the boiler in the cold area being provided configured to clean the boiler tubes of the heat exchanger by moving up and down turbulators provided in the boiler tubes. The up and down movement can also be understood as the reciprocating movement of the turbulators in the boiler tubes in the longitudinal direction of the boiler tubes.

According to a development, a biomass heating system is provided, with a fire bed height measuring mechanism being arranged in the combustion chamber above the rotary grate; wherein the firebed height measurement mechanism comprises a fuel level flap mounted on a pivot and having a major surface; wherein a surface parallel of the main surface of the fuel level flap is provided at an angle to a central axis of the axis of rotation, the angle preferably being greater than 20 degrees.

Although all the above individual features and details of an aspect of the invention and the developments of this aspect are described in connection with the biomass heating system, these individual features and details are also disclosed as such independently of the biomass heating system.

For example, a combustion chamber slope of a secondary combustion zone of a combustion chamber with the features and properties mentioned herein is disclosed, which is (only) suitable for a biomass heating system. In this respect, a combustion chamber incline for a secondary combustion zone of a combustion chamber of a biomass heating system with the features and properties mentioned herein is disclosed.

Furthermore, for example, a rotary grate for a combustion chamber of a biomass heating system with its features and properties mentioned herein is disclosed.

Furthermore, for example, a plurality of combustion chamber bricks for a combustion chamber of a biomass heating system with the features and properties mentioned herein is disclosed.

Furthermore, for example, an integrated electrostatic filter device for a biomass heating system with the features and properties mentioned herein is disclosed.

Furthermore, for example, a plurality of boiler tubes for a biomass heating system with the features and properties mentioned herein are disclosed.

Furthermore, for example, a ember bed height measuring mechanism for a biomass heating system with the features and properties mentioned herein is disclosed.

Furthermore, for example, as such, a fuel level flap for a biomass heating system with the features and properties mentioned herein is also disclosed.

Fig. 1

zeigt eine dreidimensionale Überblicksansicht einer Biomasse-Heizanlage gemäß einer Ausführungsform der Erfindung;

Fig. 2

zeigt eine Querschnittsansicht durch die Biomasse-Heizanlage der Fig. 1, welche entlang einer Schnittlinie SL1 vorgenommen wurde und welche aus der Seitenansicht S betrachtet dargestellt ist;

Fig. 3

zeigt ebenso eine Querschnittsansicht durch die Biomasse-Heizanlage der Fig. 1 mit einer Darstellung des Strömungsverlaufs, wobei die Querschnittsansicht entlang einer Schnittlinie SL1 vorgenommen wurde und aus der Seitenansicht S betrachtet dargestellt ist;

Fig. 4

zeigt eine Teilansicht der Fig. 2, die eine Brennkammergeometrie des Kessels der Fig. 2 und Fig. 3 darstellt;

Fig. 5

zeigt eine Schnittansicht durch den Kessel bzw. die Brennkammer des Kessels entlang der Vertikalschnittlinie A2 der Fig. 4;

Fig. 6

zeigt eine dreidimensionale Schnittansicht auf die Primärverbrennungszone der Brennkammer mit dem Drehrost der Fig. 4;

Fig. 7

zeigt entsprechend zur Fig. 6 eine Explosionsdarstellung der Brennkammersteine;

Fig. 8

zeigt eine Ausschnitt-Detailansicht der Fig. 2;

Fig. 9

zeigt eine Reinigungseinrichtung, mit der sowohl der Wärmetauscher als auch die Filtereinrichtung der Fig. 2 automatisch gereinigt werden können;

Fig. 10

zeigt eine Turbulatorhalterung in herausgestellter und vergrößerter Form;

Fig. 11

zeigt eine Abreinigungsmechanik in einem ersten Zustand, wobei sich sowohl die Turbulatorhalterungen der Fig. 10 als auch eine Käfighalterung in einer unteren Position befinden;

Fig. 12

zeigt die Abreinigungsmechanik in einem zweiten Zustand, wobei sich sowohl die Turbulatorhalterungen der Fig. 10 als auch die Käfighalterung in einer oberen Position befinden;

Fig. 13

zeigt eine Querschnittsansicht durch eine Biomasse-Heizanlage 1 gemäß einer Abwandlung der Biomasse-Heizanlage der Fig. 1 und Fig. 2, welche aus der Seitenansicht S betrachtet dargestellt ist;

Fig. 14

zeigt eine Draufsicht auf ein freigestelltes Schubglied 74 aus Richtung der Hinterseite der Biomasse-Heizanlage 1 der Fig. 13;

Fig. 15

zeigt eine Draufsicht auf ein freigestelltes Schubglied 74 aus Richtung der Hinterseite der Biomasse-Heizanlage 1 der Fig. 13 und Fig. 14 zusammen mit weiteren Anlagenteilen der Biomasse-Heizanlage 1 der Fig. 13;

Fig. 16

zeigt eine Hinteransicht der Biomasse-Heizanlage 1 der Fig. 13 und das Schubglied 74 der Fig. 14 und Fig. 15 im Ausgangs- oder Ruhezustand der Reinigungseinrichtung 9;

Fig. 17

zeigt eine Ansicht von schräg hinten auf die Biomasse-Heizanlage 1 der Fig. 13 im Ausgangs- oder Ruhezustand mit Einblick in die Biomasse-Heizanlage 1;

Fig. 18

zeigt eine Hinteransicht der Biomasse-Heizanlage 1 der Fig. 13 und das Schubglied 74 der Fig. 14 und Fig. 15 im Schubzustand der Reinigungseinrichtung 9;

Fig. 19

zeigt eine Ansicht von schräg hinten auf die Biomasse-Heizanlage 1 der Fig. 13 im Schubzustand der Reinigungseinrichtung 9 mit Einblick in die Biomasse-Heizanlage 1;

Fig. 20

zeigt eine Hinteransicht der Biomasse-Heizanlage 1 der Fig. 13 und das Schubglied 74 der Fig. 14 und Fig. 15 im Maximalhubzustand der Reinigungseinrichtung 9;

Fig. 21

zeigt eine Ansicht von schräg hinten auf die Biomasse-Heizanlage 1 der Fig. 13 im Schubzustand der Reinigungseinrichtung 9 mit Einblick in die Biomasse-Heizanlage 1;

Fig. 22

zeigt eine Hinteransicht der Biomasse-Heizanlage 1 der Fig. 13 und das Schubglied 74 der Fig. 14 und Fig. 15 im Fallzustand der Reinigungseinrichtung 9;

Fig. 23

zeigt eine Ansicht von schräg hinten auf die Biomasse-Heizanlage 1 der Fig. 13 im Fallzustand der Reinigungseinrichtung 9 mit Einblick in die Biomasse-Heizanlage 1;

Fig. 24

zeigt eine alternative Ausführung des Schubglieds 74.

The biomass heating system according to the invention is explained in more detail below in exemplary embodiments and individual aspects with reference to the figures of the drawing:

1

shows a three-dimensional overview of a biomass heating system according to an embodiment of the invention;

2

shows a cross-sectional view through the biomass heating system 1 , which was taken along a section line SL1 and which is shown viewed from the side view S;

3

also shows a cross-sectional view through the biomass heating system of FIG 1 with an illustration of the flow path, wherein the cross-sectional view was taken along a section line SL1 and is shown viewed from the side S;

4

shows a partial view of the 2 , which has a combustion chamber geometry of the boiler 2 and 3 represents;

figure 5

shows a sectional view through the boiler or the combustion chamber of the boiler along the vertical section line A2 of FIG 4 ;

6

shows a three-dimensional sectional view of the primary combustion zone of the combustion chamber with the rotary grate 4 ;

7

shows according to 6 an exploded view of the combustion chamber bricks;

8

shows a detail view of the 2 ;

9

shows a cleaning device with which both the heat exchanger and the filter device of the 2 can be cleaned automatically;

10

shows a turbulator mount in exposed and enlarged form;

11

shows a cleaning mechanism in a first state, with both the turbulator mounts of 10 and a cage mount are in a down position;

12

shows the cleaning mechanism in a second state, with both the turbulator mounts of 10 and the cage mount are in an up position;

13

shows a cross-sectional view through a biomass heating system 1 according to a modification of the biomass heating system of FIG 1 and 2 , which is shown viewed from side view S;

14

FIG. 1 shows a top view of an exposed thrust member 74 from the rear of the biomass heating system 1 of FIG 13 ;

15

FIG. 1 shows a top view of an exposed thrust member 74 from the rear of the biomass heating system 1 of FIG 13 and 14 together with other plant parts of the biomass heating system 1 of 13 ;

16

shows a rear view of the biomass heating system 1 of 13 and the thrust member 74 of 14 and 15 in the initial or idle state of the cleaning device 9;

17

shows an oblique view of the biomass heating system 1 from behind 13 in the initial or idle state with a view of the biomass heating system 1;

18

shows a rear view of the biomass heating system 1 of 13 and the thrust member 74 of 14 and 15 in the pushing state of the cleaning device 9;

19

shows an oblique view of the biomass heating system 1 from behind 13 in the overrun condition of the cleaning device 9 with a view of the biomass heating system 1;

20

shows a rear view of the biomass heating system 1 of 13 and the thrust member 74 of 14 and 15 in the maximum stroke state of the cleaning device 9;

21

shows an oblique view of the biomass heating system 1 from behind 13 in the overrun condition of the cleaning device 9 with a view of the biomass heating system 1;

22

shows a rear view of the biomass heating system 1 of 13 and the thrust member 74 of 14 and 15 in the case state of the cleaning device 9;

23

shows an oblique view of the biomass heating system 1 from behind 13 in the case of the cleaning device 9 with a view of the biomass heating system 1;

24

shows an alternative embodiment of the thrust member 74.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

Various embodiments of the present disclosure are disclosed below with reference to the accompanying drawings, by way of example only. However, embodiments and terms used therein are not intended to limit the present disclosure to particular embodiments, and it should be construed to include various modifications, equivalents, and/or alternatives according to the embodiments of the present disclosure.

If more general terms are used in the description for features or elements shown in the figures, it is intended that not only the specific feature or element is disclosed in the figures for the person skilled in the art, but also the more general technical teaching.

With respect to the description of the figures, the same reference numbers can be used in the individual figures to refer to similar or technically corresponding elements. Furthermore, for the sake of clarity, more elements or features can be shown with reference symbols in individual detailed or sectional views than in the overview views. It can be assumed that these elements or features are also disclosed accordingly in the overview presentations, even if they are not explicitly listed there.

It is to be understood that a singular form of a noun corresponding to an object may include one or more of the things, unless the context in question clearly indicates otherwise.

In the present disclosure, an expression such as "A or B", "at least one of "A or/and B" or "one or more of A or/and B" can include any possible combination of features listed together. Expressions such as "first ", "secondary", "primary" or "secondary" used herein represent and do not limit various elements regardless of their order and/or importance. When an element (e.g., a first element) is described as being "operably" or "communicatively" coupled or connected to another element (e.g., a second element), the element may be directly connected to the other element become or are connected to the other element via another element (e.g. a third element).

For example, a phrase "configured for" (or "configured for") as used in the present disclosure may be replaced with "suitable for," "suitable for," "adapted for," "made for," "capable of," or "designed for." depending on what is technically possible. Alternatively, in a particular situation, a phrase "device configured to" or "set up to" may mean that the device can operate in conjunction with another device or component, or perform a corresponding function.

All sizes specified in "mm" are to be understood as a size range of +- 1 mm around the specified value, unless another tolerance or other ranges are explicitly stated. All dimensions and sizes are only examples.

It should be noted that the present individual aspects, for example the rotary grate, the combustion chamber or the filter device, are disclosed here separately from or separately from the biomass heating system as individual parts or individual devices. It is therefore clear to the person skilled in the art that individual aspects or parts of the system are also disclosed here on their own. In the present case, the individual aspects or parts of the system are disclosed in particular in the sub-chapters marked by brackets. It is envisaged that these individual aspects can also be claimed separately.

Furthermore, for the sake of clarity, not all features and elements are individually identified in the figures, especially if they are repeated. There are Rather, the elements and features are each designated as an example. Analogous or identical elements are then to be understood as such.

(biomass heating system)

1 shows a three-dimensional overview of the biomass heating system 1 according to an exemplary embodiment of the invention.

The arrow V in the figures indicates the front view of the plant 1, and the arrow S in the figures indicates the side view of the plant 1.

The biomass heating system 1 has a boiler 11 which is mounted on a base 12 of the boiler. The boiler 11 has a boiler housing 13, for example made of sheet steel.

In the front part of the boiler 11 there is a combustion device 2 (not shown), which can be reached via a first maintenance opening with a closure 21 . A rotary mechanism mount 22 for a rotary grate 25 (not shown) supports a rotary mechanism 23 with which drive forces can be transmitted to bearing axles 81 of the rotary grate 25 .

In the central part of the boiler 11 there is a heat exchanger 3 (not shown), which can be reached from above via a second maintenance opening with a closure 31 .

In the rear of the vessel 11 is an optional filter assembly 4 (not shown) having an electrode 44 (not shown) suspended by an insulating electrode support 43 and powered by an electrode supply line 42 . The exhaust gas from the biomass heating system 1 is discharged via an exhaust gas outlet 41 which is arranged downstream of the filter device 4 in terms of flow. A fan can be provided here.

A recirculation device 5 is provided downstream of the boiler 11, which recirculates part of the exhaust gas via recirculation channels 51, 53 and 54 and flaps 52 for cooling the combustion process and reuse in the combustion process.

Furthermore, the biomass heating system 1 has a fuel supply 6, with which the fuel is conveyed in a controlled manner to the combustion device 2 in the primary combustion zone 26 from the side onto the rotary grate 25. The fuel supply 6 has a cell wheel sluice 61 with a fuel supply opening 65, the cell wheel sluice 61 having a drive motor 66 with control electronics. An axle 62 driven by the drive motor 66 drives a transmission mechanism 63 which can drive a fuel feed screw 67 (not shown) so that the fuel in a fuel feed channel 64 is fed to the combustion device 2 .

In the lower part of the biomass heating system 1 there is an ash removal device 7 which has an ash discharge screw 71 in an ash discharge channel which is operated by a drive unit 72 .

2 now shows a cross-sectional view through the biomass heating system 1 of FIG 1 , which was taken along a section line SL1 and which is shown viewed from the side S. In the corresponding 3 , which has the same cut as 2 represents, for the sake of clarity, the flows of the flue gas, and fluidic cross-sections are shown schematically. to 3 it should be noted that individual areas compared to the 2 are shown grayed out. This is only for clarity 3 and the visibility of the flow arrows S5, S6 and S7.

From left to right are in 2 the combustion device 2, the heat exchanger 3 and an (optional) filter device 4 of the boiler 11 are provided. The boiler 11 is mounted on the boiler base 12 and has a multi-walled boiler housing 13 in which water or another fluid heat exchange medium can circulate. To the A water circulation device 14 with a pump, valves, lines, etc. is provided for the supply and removal of the heat exchange medium.

The combustion device 2 has a combustion chamber 24 in which the combustion process of the fuel takes place in the core. The combustion chamber 24 has a multi-part rotary grate 25 on which the fuel bed 28 rests. The multi-part rotary grate 25 is rotatably mounted by means of a plurality of bearing axles 81 .

Further referring to 2 For example, the primary combustion zone 26 of the combustor 24 is encompassed by (a plurality of) combustor brick(s) 29 , whereby the combustor bricks 29 define the geometry of the primary combustion zone 26 . The cross-section of the primary combustion zone 26 (for example) along horizontal section line A1 is substantially oval (for example 380mm +/- 60mm x 320mm +/- 60mm; it should be noted that some of the above size combinations may also result in a circular cross-section). The arrow S1 shows the flow from the secondary air nozzle 291 schematically, this flow (this is shown purely schematically) having a twist induced by the secondary air nozzles 291 in order to improve the mixing of the flue gas.

The secondary air nozzles 291 are designed in such a way that they introduce the secondary air (preheated by the combustion chamber bricks 29) tangentially into the combustion chamber 24 with its oval cross section there. This creates a flow S1 with vortices or twists, which runs roughly spirally or helically upwards. In other words, a spiral flow running upwards and rotating about a vertical axis is formed.

The combustion chamber bricks 29 form the inner lining of the primary combustion zone 26, store heat and are directly exposed to the fire. The combustion chamber stones 29 thus also protect the other material of the combustion chamber 24 , for example cast iron, from the direct effect of the flames in the combustion chamber 24 . The combustion chamber stones 29 are preferably adapted to the shape of the grate 25 . The combustion chamber bricks 29 also have secondary air or recirculation nozzles 291 on, which recirculate the flue gas in the primary combustion zone 26 for re-participation in the combustion process and in particular for cooling as required. The secondary air nozzles 291 are not aligned with the center of the primary combustion zone 26, but are aligned off-centre in order to cause a swirl in the flow in the primary combustion zone 26 (ie, a swirling and turbulent flow). The combustion chamber bricks 29 will be explained in more detail later. Insulation 311 is provided at the boiler tube entrance. The oval cross-sectional shape of the primary combustion zone 26 (and the nozzle) and the length and position of the secondary air nozzles 291 favor the formation and maintenance of a turbulent flow, preferably up to the ceiling of the combustion chamber 24.

A secondary combustion zone 27 adjoins the primary combustion zone 26 of the combustion chamber 26, either at the level of the combustion chamber nozzles 291 (from a functional or combustion-related point of view) or at the level of the combustion chamber nozzle 203 (from a purely structural or constructional point of view) and defines the radiant part of the combustion chamber 26. In the radiant part, the flue gas produced during combustion releases its thermal energy mainly through thermal radiation, in particular to the heat exchange medium, which is located in the two left-hand chambers for the heat exchange medium 38 . The corresponding flue gas flows are in 3 indicated purely by way of example by the arrows S2 and S3. These turbulent flows may also contain slight backflows or other turbulences, which are not represented by the purely schematic arrows S2 and S3. However, the basic principle of the development of the flow in the combustion chamber 24 is clear and can be calculated by a person skilled in the art based on the arrows S2 and S3.

Caused by the secondary air injection, pronounced twisting or rotating or turbulent flows form in the isolated or limited combustion chamber 24 . The oval combustion chamber geometry 24 in particular contributes to the fact that the turbulent flow can develop undisturbed or optimally.

After exiting the nozzle 203, which bundles these turbulent flows again, candle-flame-shaped rotary flows S2 appear, which are advantageous can reach up to the combustion chamber ceiling 204, so that the available space in the combustion chamber 24 is better utilized. The turbulent flows are concentrated in the center of the combustion chamber A2 and make ideal use of the volume of the secondary combustion zone 27 . Furthermore, the constriction, which represents the combustion chamber nozzle 203 for the turbulent flows, reduces the rotational flows, with which turbulences are generated to improve the mixing of the air/flue gas mixture. Cross-mixing therefore takes place through the constriction or constriction through the combustion chamber nozzle 203 . However, the rotational momentum of the flows is at least partially maintained above the combustion chamber nozzle 203, which maintains the propagation of these flows up to the combustion chamber ceiling 204.

The secondary air nozzles 291 are integrated into the elliptical or oval cross-section of the combustion chamber 24 in such a way that, due to their length and their orientation, they induce turbulent flows which cause the flue gas/secondary air mixture to rotate and thereby (again in combination with the combustion chamber nozzle 203 positioned above improved) enable complete combustion with minimal excess air and thus maximum efficiency.

The secondary air supply is designed in such a way that it cools the hot combustion chamber bricks 29 by flowing around them and the secondary air itself is preheated in return, whereby the combustion rate of the flue gases is accelerated and the complete combustion even at extreme partial load (e.g. 30% the nominal load) is ensured.

The first maintenance opening 21 is insulated with an insulating material such as Vermiculite ^™ . The present secondary combustion zone 27 is set up in such a way that burnout of the flue gas is ensured. The special geometric design of the secondary combustion zone 27 will be explained in more detail later.

After the secondary combustion zone 27, the flue gas flows into the heat exchange device 3, which is a bundle of parallel provided Boiler tubes 32 has. The flue gas now flows downwards in the boiler tubes 32, as in 3 indicated by the arrows S4. This part of the flow can also be referred to as the convection part, since the heat dissipation of the flue gas takes place essentially on the boiler tube walls via forced convection. Due to the temperature gradients in the heat exchanger medium, for example in the water, caused in the boiler 11, natural convection of the water occurs, which promotes thorough mixing of the boiler water.

Spring turbulators 36 and spiral or band turbulators 37 are arranged in the boiler tubes 32 in order to improve the efficiency of the heat exchange device 4 . This will be explained in more detail later.

The outlet of the boiler tubes 32 opens into the turning chamber 35 via the turning chamber entry 34 or inlet. If the filter device 4 is not provided, the flue gas is discharged upwards again in the boiler 11 . The other case of the optional filter device 4 is in the 2 and 3 shown. In the process, the flue gas is fed back up into the filter device 4 after the turning chamber 35 (cf. arrows S5), which in the present example is an electrostatic filter device 4. Flow screens can be provided at the inlet 44 of the filter device 4, which even out the inflow of the flue gas into the filter.

Electrostatic dust filters, also known as electrostatic precipitators, are devices for separating particles from gases that are based on the electrostatic principle. These filter devices are used in particular for the electrical cleaning of exhaust gases. With electrostatic precipitators, dust particles are electrically charged by a corona discharge of a spray electrode and drawn to the oppositely charged electrode (collecting electrode). The corona discharge takes place on a suitable, charged high-voltage electrode (also known as a discharge electrode) inside the electrostatic precipitator. The electrode is preferably designed with protruding tips and possibly sharp edges, because the density of the field lines and thus also the electric field strength is greatest there and the corona discharge is thus favored. The opposite electrode (precipitation electrode) usually consists of a grounded exhaust pipe section that is mounted around the electrode. The degree of separation of an electrostatic precipitator depends in particular on the dwell time of the exhaust gases in the filter system and the voltage between the spray and separation electrodes. The rectified high voltage required for this is provided by a high-voltage generating device (not shown). The high-voltage generation system and the holder for the electrode must be protected from dust and dirt in order to avoid unwanted leakage currents and to extend the service life of system 1.

As in 2 shown is a rod-shaped electrode 45 (which is preferably designed like an elongated, plate-shaped steel spring, cf. 11 ) held approximately centrally in an approximately chimney-shaped interior of the filter device 4. The electrode 45 consists at least largely of high-quality spring steel or chromium steel and is held by an electrode holder 43 via a high-voltage insulator, ie an electrode insulation 46 .

The (spray) electrode 45 hangs downwards into the interior of the filter device 4 so that it can vibrate. The electrode 45 can, for example, vibrate back and forth transversely to the longitudinal axis of the electrode 45 .

A cage 48 simultaneously serves as a counter-electrode and as a cleaning mechanism for the filter device 4. The cage 48 is connected to ground or earth potential. Due to the prevailing potential difference, the exhaust gas flowing in the filter device 4 is filtered, cf. the arrows S6, as explained above. In the case of cleaning of the filter device 4, the electrode 45 is switched off. The cage 48 preferably has an octagonal regular cross-sectional profile, as can be seen, for example, in FIG 9 can be taken. The cage 48 can preferably be laser cut during manufacture.

After leaving the heat exchanger 3, the flue gas flows through the turning chamber 34 into the inlet 44 of the filter device 4.

The (optional) filter device 4 is optionally provided fully integrated in the boiler 11, so that the wall surface facing the heat exchanger 3 and flushed through by the heat exchange medium is also used for heat exchange from the direction of the filter device 4, with which the efficiency of the system 1 is further improved. In this way, at least part of the wall of the filter device 4 can be flushed with the heat exchange medium, with the result that at least part of this wall is cooled with boiler water.

The cleaned exhaust gas flows out of the filter device 4 at the filter outlet 47, as indicated by the arrows S7. After leaving the filter, part of the exhaust gas is returned to the primary combustion zone 26 via the recirculation device 5 . This will also be explained in more detail later. The remaining part of the exhaust gas is conducted out of the boiler 11 via the exhaust gas outlet 41 .

The ash removal device 7 is arranged in the lower part of the boiler 11 . The ash that has been separated and fallen out, for example from the combustion chamber 24, the boiler tubes 32 and the filter device 4, is discharged laterally out of the boiler 11 via an ash discharge screw 71. The drive unit 72 , which has an optional gear and a freewheel 73 , is provided for driving the ash removal 7 and a cleaning device 9 (see later). A thrust member 74, which will be explained in more detail later, is used with a crank element 77 as a transmission element between the motor and other elements of the cleaning device 9 (cf. also 13 et seq.). The mechanical components of the cleaning device are mounted or held in a frame 76 which is welded to the boiler base 12, for example.

The combustor 24 and boiler 11 of this embodiment were calculated using CFD simulations. Furthermore, practical experiments were carried out to confirm the CFD simulations. The starting point for the considerations were calculations for a 100 kW boiler, although a power range from 20 to 500 kW was taken into account.

A CFD simulation (CFD = Computational Fluid Dynamics = numerical fluid mechanics) is the spatially and temporally resolved simulation of flow and heat conduction processes. The flow processes can be laminar and/or turbulent, accompanied by chemical reactions, or it can be a multi-phase system. CFD simulations are therefore well suited as a design and optimization tool. In the present invention, CFD simulations were used to optimize the fluidic parameters in such a way that the objects of the invention listed above are achieved. In particular, as a result, the mechanical design and dimensioning of the boiler 11, the combustion chamber 24, the secondary air nozzles 291 and the combustion chamber nozzle 203 were largely defined by the CFD simulation and also by associated practical experiments. The simulation results are based on a flow simulation taking heat transfer into account.

The components of the biomass heating system 1 and the boiler 11 listed above, which are results of the CFD simulations, are described in more detail below.

(combustion chamber)

The design of the combustor shape is important in order to be able to meet the task requirements. The shape and geometry of the combustion chamber should ensure the best possible turbulent mixing and homogenization of the flow across the cross-section of the flue gas duct, minimization of the combustion volume and a reduction in excess air and the recirculation ratio (efficiency, operating costs), a reduction in CO and CxHx emissions, NOx emissions, dust emissions, a reduction in local temperature peaks (fouling and slagging) and a reduction in local flue gas velocity peaks (material stress and erosion) can be achieved.

the 4 showing a partial view of the 2 is, and the figure 5 , which is a sectional view through the boiler 11 along the vertical section line A2, represent a combustion chamber geometry that meets the above-mentioned requirements for biomass heating systems over a wide power range of, for example, 20 to 500 kW. Incidentally, the vertical section line A2 can also be understood as the middle or central axis of the oval combustion chamber 24 .

• BK1 = 172 mm +- 40 mm, vorzugsweise +- 17 mm;
• BK2 = 300 mm +- 50 mm, vorzugsweise +- 30 mm;
• BK3 = 430 mm +- 80 mm, vorzugsweise +- 40 mm;
• BK4 = 538 mm +- 80 mm, vorzugsweise +- 50 mm;
• BK5 = (BK3 - BK2) / 2 = bspw. 65 mm +- 30 mm, vorzugsweise +- 20 mm;
• BK6 = 307 mm +- 50 mm, vorzugsweise +- 20 mm;
• BK7 = 82 mm +- 20 mm, vorzugsweise +- 20 mm;
• BK8 = 379 mm +- 40 mm, vorzugsweise +- 20 mm;
• BK9 = 470 mm +- 50 mm, vorzugsweise +- 20 mm;
• BK10 = 232 mm +- 40 mm, vorzugsweise +- 20 mm;
• BK11 = 380 mm +- 60 mm, vorzugsweise +- 30 mm;
• BK12 = 460 mm +- 80 mm, vorzugsweise +- 30 mm.

The in the Figures 3 and 4 The dimensions given and determined via CFD calculations and practical experiments for an example boiler with approx. 100 kW are as follows:

• BK1 = 172 mm +- 40 mm, preferably +- 17 mm;
• BK2 = 300 mm +- 50 mm, preferably +- 30 mm;
• BK3 = 430 mm +- 80 mm, preferably +- 40 mm;
• BK4 = 538 mm +- 80 mm, preferably +- 50 mm;
• BK5 = (BK3 - BK2) / 2 = e.g. 65 mm +- 30 mm, preferably +- 20 mm;
• BK6 = 307 mm +- 50 mm, preferably +- 20 mm;
• BK7 = 82mm +- 20mm, preferably +- 20mm;
• BK8 = 379 mm +- 40 mm, preferably +- 20 mm;
• BK9 = 470mm +- 50mm, preferably +- 20mm;
• BK10 = 232 mm +- 40 mm, preferably +- 20 mm;
• BK11 = 380mm +- 60mm, preferably +- 30mm;
• BK12 = 460 mm +- 80 mm, preferably +- 30 mm.

In the present case, both the geometries of the primary combustion zone 26 and the secondary combustion zone 27 of the combustion chamber 24 are optimized with these values. The specified size ranges are ranges with which the requirements are (approximately) fulfilled as well as with the specified exact values.

A chamber geometry of the primary combustion zone 26 and the combustion chamber 24 (or an inner volume of the primary combustion zone 26 of the combustion chamber 24) can preferably be defined using the following basic parameters:
A volume with an oval horizontal base measuring 380 mm +- 60 mm (preferably +-30 mm) x 320 mm +- 60 mm (preferably +-30 mm), and a height of 538 mm +- 80 mm ( preferably +- 50 mm).

The size information given above can also be applied to boilers in other output classes (e.g. 50 kW or 200 kW) scaled in relation to one another.

As a further development, the volume defined above can have an upper opening in the form of a combustion chamber nozzle 203, which is provided in the secondary combustion zone 27 of the combustion chamber 24, which has a combustion chamber slope 202 protruding into the secondary combustion zone 27, which preferably contains the heat exchange medium 38. Combustion chamber slope 202 reduces the cross section of secondary combustion zone 27. Combustion chamber slope 202 is inclined by an angle k of at least 5%, preferably by an angle k of at least 15% and even more preferably by at least an angle k of 19% with respect to an imaginary Horizontal or straight combustion chamber ceiling H (cf. the dashed horizontal line H in 4 ) intended.

In addition, a combustion chamber cover 204 is provided, likewise inclined in the direction of the inlet 33 . The combustion chamber 24 in the secondary combustion zone 27 thus has the combustion chamber ceiling 204 which is provided inclined upwards in the direction of the inlet 33 of the heat exchanger 3 . This combustion chamber ceiling 204 extends in section 2 at least largely straight or rectilinear and inclined. The angle of inclination of the straight or flat combustion chamber ceiling 204 can preferably be 4 to 15 degrees relative to the (fictitious) horizontal.

With the combustion chamber ceiling 204, a further (ceiling) slope is provided in the combustion chamber 24 in front of the inlet 33, which forms a funnel together with the combustion chamber slope 202. This funnel turns the swirling or eddy flow directed upwards to the side and deflects this flow more or less horizontally. Due to the already turbulent upward flow and the funnel shape in front of the inlet 33, it is ensured that all heat exchanger tubes 32 or boiler tubes 32 are flown evenly, whereby an evenly distributed flow of the flue gas in all boiler tubes 32 is ensured. This optimizes the heat transfer in the heat exchanger 3 considerably.

In particular, the combination of the vertical and horizontal inclines 203, 204 in the secondary combustion zone in combination as the inflow geometry in the convective boiler can achieve a uniform distribution of the flue gas over the convective boiler tubes.

The combustion chamber slope 202 serves to homogenize the flow S3 in the direction of the heat exchanger 3 and thus the flow through the boiler tubes 32. This causes the flue gas to be distributed as evenly as possible to the individual boiler tubes in order to optimize the heat transfer there.

In detail, the combination of the inclines with the inflow cross section of the boiler rotates the flue gas flow in such a way that the flue gas flow or the flow rate is distributed as evenly as possible over the respective boiler tubes 32 .

In the prior art, there are often combustion chambers with a rectangular or polygonal combustion chamber and nozzle, but the irregular shape of the combustion chamber and the nozzle and their interaction represent a further obstacle to an even air distribution and a good mixture of air and fuel and thus good combustion , as recognized herein. Especially with an angular geometry of the combustion chamber, flow threads or Preferential flows, which disadvantageously lead to an uneven flow of the heat exchanger tubes 32.

Therefore, in the present case, the combustion chamber 24 is provided without dead corners or dead edges.

It was thus recognized in the present case that the geometry of the combustion chamber (and the entire course of flow in the boiler) plays a decisive role in the considerations for optimizing the biomass heating system 1 . For this reason, the oval or round basic geometry described here without dead corners was chosen (in contrast to the usual rectangular or polygonal or purely cylindrical shapes). In addition, this basic geometry of the combustion chamber and its structure has been optimized with the dimensions/dimensional ranges specified above. These dimensions/dimensional ranges are selected in such a way that, in particular, different fuels (wood chips and pellets) with different qualities (for example with different water contents) can be burned with a very high level of efficiency. This has been shown by practical tests and CFD simulations.

In particular, the primary combustion zone 26 of the combustion chamber 24 can comprise a volume which preferably has an oval or approximately circular horizontal cross-section on the outer circumference (such a cross-section is shown in 2 marked with A1 as an example). This horizontal cross section can also preferably represent the base area of the primary combustion zone 26 of the combustion chamber 24 . The combustion chamber 24 can have an approximately constant cross section over the height indicated by the double arrow BK4. In this respect, the primary combustion zone 24 can have an approximately oval-cylindrical volume. Preferably, the side walls and base (grate) of the primary combustion zone 26 may be perpendicular to one another. The bevels 203, 204 described above can be provided as integrated walls of the combustion chamber 24, with the bevels 203, 204 forming a funnel which opens into the inlet 33 of the heat exchanger 33 and has the smallest cross section there.

The term "approximately" is used above because of course individual notches, design-related deviations or small asymmetries can be present, for example at the transitions of the individual combustion chamber bricks 29 to one another. However, these minor deviations only play a subordinate role in terms of flow technology.

The horizontal cross section of the combustion chamber 24 and in particular of the primary combustion zone 26 of the combustion chamber 24 can also preferably be regular. Further, the horizontal cross-section of the combustor 24, and particularly the primary combustion zone 26 of the combustor 24, may preferably be a regular (and/or symmetrical) ellipse.

In addition, the horizontal cross section (the outer circumference) of the primary combustion zone 26 can be made constant over a predetermined height (for example, 20 cm).

An oval-cylindrical primary combustion zone 26 of the combustion chamber 24 is thus provided in the present case, which, according to CFD calculations, enables a significantly more uniform and better air distribution in the combustion chamber 24 than in the case of rectangular combustion chambers of the prior art. The lack of dead spaces also avoids zones in the combustion chamber with poor air flow, which increases efficiency and reduces slag formation.

Likewise, the nozzle 203 in the combustion chamber 24 is designed as an oval or approximately circular constriction in order to further optimize the flow conditions. The swirl of the flow in the primary combustion zone 26 explained above, which is caused by the specially designed secondary air nozzles 291 according to the invention, leads to a roughly helical or spiral upward flow pattern, with an equally oval or approximately circular nozzle favoring this flow pattern, and not as usual rectangular nozzles interferes. This optimized nozzle 203 bundles the flue gas-air mixture flowing upwards rotating and ensures better mixing, preservation of the eddy currents in the Secondary combustion zone 27 and thus for complete combustion. This also minimizes the excess air required. This improves the combustion process and increases efficiency.

The combination of the secondary air nozzles 291 explained above and the eddy currents induced thereby with the optimized nozzle 203 serves in particular to bundle the flue gas/air mixture rotating upwards. This ensures at least approximately complete combustion in the secondary combustion zone 27.

Thus, a turbulent or swirling flow is bundled through the nozzle 203 and directed upwards, with the result that this flow extends further upwards than is usual in the prior art. As can be seen by the person skilled in the art from the laws of physics relating to the angular momentum, this is due to the reduction in the distance of the swirling air flow to the rotation or swirl center axis, which is forced by the nozzle 203 (compare analogously to the physics of the pirouette effect).

In addition, the course of the flow in the secondary combustion zone 27 and from the secondary combustion zone 27 to the boiler tubes 32 is presently optimized, as explained in more detail below.

The combustion chamber slope 202 of 4 , which without a reference number in the 2 and 3 can be seen and where the combustion chamber 25 (or its cross-section) tapers at least approximately linearly from bottom to top, according to CFD calculations ensures that the flue gas flow in the direction of the heat exchange device 4 is made more uniform, which means that its efficiency can be improved. The horizontal cross-sectional area of the combustion chamber 25 tapers from the beginning to the end of the combustion chamber slope 202, preferably by at least 5%. The combustion chamber slope 202 is provided on the side of the combustion chamber 25 to the heat exchange device 4 and is provided rounded at the point of maximum narrowing. Parallel or straight combustion chamber walls without a taper (so as not to restrict the flow of flue gas) are common in the state of the art impede). In addition, there is, individually or in combination, the combustion chamber cover 204, which extends obliquely upwards towards the inlet 33 to the horizontal and diverts the turbulent flows in the secondary combustion zone 27 laterally, thereby equalizing their flow velocity distribution.

The inflow or deflection of the flue gas flow in front of the tube bundle heat exchanger is designed in such a way that an uneven flow of the tubes is avoided as far as possible, whereby temperature peaks in individual boiler tubes 32 can be kept low and thus the heat transfer in the heat exchanger 4 can be improved (best possible use of the heat exchanger surfaces). . As a result, the efficiency of the heat exchange device 4 is improved.

In detail, the gaseous volume flow of the flue gas is conducted through the inclined combustion chamber wall 203 at a uniform speed (even in the case of different combustion states) to the heat exchanger tubes or the boiler tubes 32. This effect is further intensified by the sloping combustion chamber ceiling 204, with a funnel effect being brought about. The result is a uniform heat distribution of the heat exchanger surfaces affecting the individual boiler tubes 32 and thus an improved use of the heat exchanger surfaces. The exhaust gas temperature is thus reduced and the efficiency increased. The flow distribution is particularly at the in the 3 shown indicator line WT1 much more evenly than in the prior art. The line WT1 represents an entry surface for the heat exchanger 3. The indicator line WT3 indicates an exemplary cross-sectional line through the filter device 4, in which the flow is set up as homogeneously as possible or is approximately evenly distributed over the cross-section of the boiler tubes 32 (due to of flow screens at the entrance of the filter device 4 and due to the geometry of the turning chamber 35). A uniform flow through the filter device 3 or the last boiler train minimizes strand formation and thereby also optimizes the separation efficiency of the filter device 4 and the heat transfer in the biomass heating system 1.

Furthermore, an ignition device 201 is provided in the lower part of the combustion chamber 25 on the fuel bed 28 . This can cause initial ignition or re-ignition of the fuel. The ignition device 201 can be a glow igniter. The ignition device is advantageously stationary and offset horizontally to the side relative to the location at which the fuel is introduced.

Furthermore, a lambda probe (not shown) can (optionally) be provided after the exit of the flue gas (ie, after S7) from the filter device. A controller (not shown) can use the lambda probe to detect the respective calorific value. The lambda probe can thus ensure the ideal mixing ratio between the fuels and the oxygen supply. Despite different fuel qualities, the result is high efficiency and higher efficiency.

This in figure 5 The fuel bed 28 shown shows a rough fuel distribution due to the feeding of the fuel from the right side of the figure 5 .

Next is in the 4 and 5 a combustion chamber nozzle 203 is shown in which a secondary combustion zone 27 is provided and which accelerates and focuses the flue gas flow. As a result, the flue gas flow is better mixed and can burn more efficiently in the post-combustion zone 27 or secondary combustion zone 27 . The area ratio of the combustion chamber nozzle 203 is in a range from 25% to 45%, but is preferably 30% to 40%, and is, for example for a 100 kW biomass heating system 1, ideally 36% +/- 1% (ratio of the measured input area to the measured exit area of the nozzle 203).

Consequently, the above information on the combustion chamber geometry of the primary combustion zone 26 together with the geometry of the secondary air nozzles 291 and the nozzle 203 represent an advantageous development of the present disclosure.

(combustion chamber bricks)

the 6 shows a three-dimensional sectional view (obliquely from above) of the primary combustion zone 26 and the isolated part of the secondary combustion zone 27 of the combustion chamber 24 with the rotary grate 25, and in particular the special design of the combustion chamber bricks 29. The 7 shows according to 6 an exploded view of the combustion chamber bricks 29. The views of 6 and 7 can preferably with the dimensions listed above 4 and 5 be executed. However, this is not necessarily the case.

The chamber wall of the primary combustion zone 26 of the combustor 24 is provided with a plurality of combustor bricks 29 in a modular construction which, among other things, facilitates manufacture and maintenance. Maintenance is facilitated in particular by the possibility of removing individual combustion chamber bricks 29.

Form-fitting grooves 261 and projections 262 (in 6 to avoid redundancies in the figures, only a few of these are designated by way of example) are provided in order to create a mechanical and largely airtight connection, in order in turn to prevent the ingress of disturbing external air. Preferably, every two at least largely symmetrical combustion chamber bricks (with the possible exception of the openings for the secondary air or the recirculated flue gas) form a complete ring. Furthermore, three rings are preferably stacked on top of one another in order to form the primary combustion zone 26 of the combustion chamber 24 which is oval-cylindrical or alternatively at least approximately circular (the latter is not shown).

Three further combustion chamber bricks 29 are provided as the upper closure, with the annular nozzle 203 being supported by two retaining bricks 264 which are placed on the upper ring 263 in a form-fitting manner. All bearing surfaces 260 have grooves 261 either for mating projections 262 and/or for the insertion of suitable sealing material.

The mounting stones 264, which are preferably symmetrical, can preferably have an inwardly inclined bevel 265 in order to make it easier for fly ash to be swept away onto the rotary grate 25.

The lower ring 263 of the combustion chamber bricks 29 rests on a base plate 251 of the rotary grate 25 . Ash is increasingly deposited on the inner edge between this lower ring 263 of the combustion chamber bricks 29 , which advantageously independently and advantageously seals this transition during operation of the biomass heating system 1 .

The openings for the recirculation nozzles 291 or secondary air nozzles 291 are provided in the middle ring of the combustion chamber bricks 29 . The secondary air nozzles 291 are provided at least approximately at the same (horizontal) height of the combustion chamber 24 in the combustion chamber bricks 29 .

Three rings of combustor bricks 29 are provided here, as this represents the most efficient way of manufacture and also of maintenance. Alternatively, 2, 4 or 5 such rings can also be provided.

The combustion chamber bricks 29 are preferably made of high-temperature silicon carbide, which makes them very wear-resistant.

The combustion chamber bricks 29 are provided as shaped bricks. The combustion chamber bricks 29 are shaped in such a way that the interior volume of the primary combustion zone 26 of the combustion chamber 24 has an oval horizontal cross section, which means that dead corners or dead spaces, which are usually not optimally flown through by the flue gas/air mixture, are avoided by an ergonomic shape, whereby the fuel present there is not is optimally burned. Due to the present shape of the combustion chamber bricks 29, the flow of primary air through the grate 25, which also suits the distribution of the fuel over the grate 25, and the possibility of unhindered turbulent flows is improved; and consequently the efficiency of combustion is improved.

The oval horizontal cross section of the primary combustion zone 26 of the combustion chamber 24 is preferably a point-symmetrical and/or regular oval with the smallest inside diameter BK3 and the largest inside diameter BK11. These measurements were the result of optimizing the primary combustion zone 26 of the combustor 24 using CFD simulation and field testing.

(heat exchanger)

In order to optimize the heat exchanger 3, CFD simulations and practical tests were again carried out in synergy with the considerations described above. It was also checked to what extent a spring turbulator or a band turbulator or a combination of both can improve the efficiency of the heat exchange process without, however, allowing the pressure loss in the heat exchanger 3 to become too great. Turbulators increase the formation of turbulence in the boiler tubes 32, which reduces the flow rate, increases the residence time of the flue gas in the boiler tube 32 and thus increases the efficiency of the heat exchange. In detail, the boundary layer of the flow on the pipe wall is broken up, which improves heat transfer. However, the more turbulent the flow, the greater the pressure loss.

In the present case, slight soiling (so-called fouling with a thickness of 1 mm) was also taken into account for all surfaces in contact with flue gas. The emissivity of such a fouling layer was set at 0.6.

The result of this optimization is in 8 shown, which is a cut-out detail view of the 2 is.

The heat exchanger 3 has a vertically arranged bundle of boiler tubes 32, each boiler tube 32 preferably being provided with both a spring and a band or spiral turbulator. The respective spring turbulator 36 preferably extends over the entire length of the respective boiler tube 32 and is designed in the shape of a spring. The respective band turbulator 37 preferably extends over about half Length of the respective boiler tube 32 and has a spiral in the axial direction of the boiler tube 32 extending band with a material thickness of 1.5 mm to 3 mm. Furthermore, the respective band turbulator 37 can also be approximately 35% to 65% of the length of the respective boiler tube 32. Each band turbulator 37 is preferably disposed with one end at the downstream end of each boiler tube 32 . The combination of spring and ribbon or spiral turbulator can also be referred to as a double turbulator. In 8 Both ribbon and spiral turbulators are shown. In the present dual turbulator, the band turbulator 37 is located within the spring turbulator 36 . However, only one type of turbulator can be used as a cleaning element, in particular for cleaning purposes. In the detail of the 8 a cleaning shaft 92 can also be seen, which extends transversely to the viewing direction.

Band turbulators 37 are provided because the band turbulator 37 increases the turbulence effect in the boiler tube 32 and causes a more homogeneous temperature and velocity profile viewed over the tube cross section, while the tube without a band turbulator preferably forms a hot streak with higher velocities in the center of the tube, which extends to the outlet of the boiler tube 32, which would adversely affect the heat transfer efficiency. The band turbulators 37 in the lower area of the boiler tubes 32 thus improve the convective heat transfer.

As an optimum example, 22 boiler tubes with a diameter of 76.1 mm and a wall thickness of 3.6 mm can be used.

The pressure loss in this case can be less than 25 Pa. In this case, the spring turbulator 36 ideally has an outside diameter of 65 mm, a pitch of 50 mm, and a profile of 10×3 mm. In this case, the band turbulator 37 can have an outer diameter of 43 mm, a pitch of 150 mm and a profile of 43 x 2 mm. A sheet metal thickness of the band turbulator can be 2 mm.

Good efficiency is achieved with 18 to 24 boiler tubes and a diameter of 70 to 85 mm with a wall thickness of 3 to 4.5 mm. Correspondingly adapted spring and band turbulators can be used.

However, in order to achieve sufficient efficiency, between 14 and 28 boiler tubes 32 with a diameter between 60 and 80 mm and a wall thickness of 2 to 5 mm can be used. In these cases, the pressure loss can be between 20 and 40 Pa, and can therefore be rated as positive. The outer diameter, pitch and profile of the spring and ribbon turbulators 36, 37 is provided to be adjusted accordingly.

The desired target temperature at the outlet of the boiler tubes 32 can preferably be between 100 and 160 degrees Celsius at rated output.

(cleaning device for the boiler)

9 shows a cleaning device 9 with which both the heat exchanger 3 and the filter device 4 can be cleaned (off) automatically. the 9 shows the cleaning device from the boiler 11 for the sake of clarity. The cleaning device 9 relates to the entire boiler 11 and thus relates to the convective part of the boiler 11 and also the last boiler pass, in which the electrostatic filter device 4 can optionally be integrated.

The cleaning device 9 has levers 921 which can transmit forces to two cleaning shafts 92 , the cleaning shafts 92 in turn being mounted in a shaft holder 93 . The cleaning shafts 92 can preferably also be mounted rotatably at another location, for example at the remote ends. The cleaning shafts 92 have extensions 94 to which the cage 48 of the filter device 4 and the turbulator holders 95 are connected and mounted via joints or via rotary bearings. In 9 only an angled extension 94 is shown as an example. However, the extension 94 or the extensions can also be rectilinear extend.

The levers 921 have at their distal end (remote from the cleaning shaft 92) lever pins 922 which protrude in the direction of the axis of the cleaning shaft 92. These lever pins engage in slots or elongated holes 743, also referred to as lever pin holes 743, which will be explained later.

The turbulator mount 95 is in 10 highlighted and enlarged. The turbulator mount 95 is designed in the manner of a comb and is preferably designed to be horizontally symmetrical. Furthermore, the turbulator holder 95 is designed as a flat piece of metal with a material thickness in the thickness direction D of between 2 and 5 mm. The turbulator mount 95 has two pivot bearing mounts 951 on its underside for connection to pivot bearing journals (not shown) of the extensions 94 of the cleaning shafts 92 . Pivot mounts 951 may have horizontal play in which pivot pins or pivot linkage 955 can reciprocate as extensions 94 lever-like move with cleaning shaft 92 as the axis of rotation as cleaning shaft 92 rotates. The extensions 94 can, for example, extend away from the cleaning shaft 92 in the lateral direction of the boiler 11 . The turbulator mount 95 and/or the cage 48 and/or the turbulators 36/37 can be attached to the distal end of the extensions 94, for example. This attachment can be done via a joint or, as described above, via a bearing, or via a game. The extensions 94 also serve as levers. A rotation is converted into a stroke and vice versa.

The extensions 94 of the cleaning shaft 92 extend radially from the cleaning shaft 92 so that they raise or lower the turbulator mount 95 (and the cleaning cage 94) as the cleaning shaft rotates.

In this respect, the extensions are provided on the cleaning shaft 92 in such a way that the rotation of the cleaning shaft 92 is converted into at least a partial vertical stroke and vice versa.

The dead weight of the turbulators 36, 37, the (optional) cage 48 and also the associated parts, such as the turbulator holder 95, acts via the extensions 92 on the cleaning shaft 92 in such a way that this rotates the cleaning shaft 92 in a predetermined direction of rotation of the cleaning shaft 92 press or the weight of these elements is converted into a torque on the cleaning shaft 92.

The weight of the parts or elements acting on the cleaning shaft 92 can be more than 10 kilograms, preferably more than 30 kilograms, in order to generate a strong torque on the central axis of the cleaning shaft 92 .

In summary, the cleaning shaft 92 or the cleaning shafts 92 serve as a transmission element/s between the cleaning elements, for example the turbulators 36, 37, and a thrust element 74, which will be explained later in relation to the Figures 13 to 24 will be explained in more detail.

Vertically protruding extensions 952 also have a plurality of recesses 954 in and with which the double turbulators 36, 37 can be attached. The recesses 954 can be at a distance from one another which corresponds to the pitch of the double turbulators 36, 37. In addition, passages 953 for the flue gas can preferably be arranged in the turbulator holder 95 in order to optimize the flow from the boiler tubes 32 into the filter device 4 . Otherwise the flat metal would be at right angles to the flow and impede it too much.

In addition, when the respective spring turbulator 36 including the spiral turbulator (double turbulator) is installed, the spiral automatically rotates under its own weight into the receptacle of the turbulator holder 95 (which can also be referred to as a receiving rod) and is thus fixed and secured. This makes assembly much easier.

the figures 11 and 12 show the cleaning mechanism 9 without the cage 48 in two different states. The cage mount 481 can be seen better here.

11 shows the cleaning mechanism 9 in a first (rest) state, with both the turbulator mounts 95 and the cage mount 481 in a lower position. A two-armed hammer 96 with a stop head 97 is attached to one of the cleaning shafts 92 . Alternatively, the impact lever 96 can also be provided with one or more arms. The impact lever 96 with the stop head 97 is set up in such a way that it can be moved to the end of the (spray) electrode 45 or can strike against it. In particular, with the accelerated movement generated by the pushing element 74, which will be explained later, the impact process can advantageously take place quickly and with a great deal of energy.

12 shows the cleaning mechanism 9 in a second (maximum stroke) state, with both the turbulator mounts 95 and the cage mount 481 in an upper position.

During the transition from the first state to the second state (and vice versa), rotation of the cleaning shafts 92 by means of the cleaning drives 91 causes both the turbulator holder 95 and the cage holder 481 to be raised vertically via the extensions 952 (and a rotary bearing linkage 955). Thus, the double turbulators 36, 37 in the boiler tubes 32 and also the cage 48 in the chimney of the filter device 4 can be moved up and down and can correspondingly clean the respective walls of fly ash or the like.

In addition, the impact lever 96 with the stop head 97 can strike the end of the (spray) electrode 45, for example during the transition from the first state to the second state. This striking at the free (ie not suspended) end of the (spray) electrode 45 has the advantage over conventional vibrating mechanisms (in which the electrode is moved on its suspension) that the (spray) electrode 45 according to its vibration characteristics after the excitation the striking itself can vibrate (ideally freely). The type of attack determines the oscillations or oscillation modes of the (spray) electrode 45 Longitudinal vibration to be struck. However, the (spray) electrode 45 can also be located on the side (in the figures 11 and 12 be struck, for example, from the direction of arrow V), so that it oscillates transversely. Or it can be the (spray) electrode 45 (as present in figures 11 and 12 shown) are attached at the end from a slightly laterally offset direction from below. In the latter case, a plurality of different vibration modes are generated in the (spray) electrode 45 (by striking), which advantageously add up in the cleaning effect and improve the efficiency of the cleaning. In particular, the shearing effect of the transverse vibration on the surface of the (spray) electrode 45 can improve the cleaning effect.

In this respect, an impact or a shock wave can occur in the elastic spring electrode 45 in the longitudinal direction of the electrode 45, which is preferably designed as an elongated plate-shaped rod. A transverse vibration of the (spray) electrode 45 can also occur due to the acting transverse forces (which are aligned transversely or at right angles to the direction of the longitudinal axis of the electrode 45).

It is also possible to generate several types of vibration at the same time. In particular, a shock wave and/or longitudinal wave combined with a transverse vibration of the electrode 45 can again lead to improved cleaning of the electrode 45.

As a result, a fully automatic cleaning during the ash removal in a common ash box at the front of the heating system (not shown) can be realized via the discharge screw 71. Likewise, the spring steel electrode 48 can be cleaned without wear and with little noise.

Furthermore, the cleaning device 9 can be manufactured simply and inexpensively in the manner described and has a simple and low-wear structure.

Furthermore, the cleaning device 9 is set up with the drive mechanism in such a way that ash residues are advantageously already removed from the first train of the boiler tubes 32 can be cleaned by the turbulators and can fall down.

In addition, the cleaning device 9 is installed in the lower, so-called "cold area" of the boiler 11, which also reduces wear, since the mechanics are not exposed to very high temperatures (i.e. the thermal load is reduced). In contrast to this, in the prior art, the cleaning mechanism is installed in the upper area of the system, which correspondingly disadvantageously increases wear.

In addition, regular automated cleaning improves the efficiency of the system 1 since the surfaces of the heat exchanger 3 are cleaner. The filter device 4 can also work more efficiently since its surfaces are also cleaner. This is also important because the electrodes of the filter device 4 become dirty faster than the convective part of the boiler 11.

In this way, cleaning of the electrodes of the filter device 4 is advantageously also possible during operation or during the operation of the boiler 11 .

(Improved Purifier 9)

13 shows a cross-sectional view through a biomass heating system 1 according to a modification of the biomass heating system of FIG 1 and 2 , which is shown viewed from the side view S.

The modification of 13 of the biomass heating system 1 of 1 concerns minor changes to the number of boiler tubes 32 and the dimensioning of the biomass heating system 1, as well as a further improvement in the cleaning device 9 and the ash removal 7.

The same reference numerals or components shown in the same way 1 , 2 and 13 are used to refer to similar or technically equivalent items. Next, for the sake of clarity in individual detailed or excerpt views that belong to the 1 , 2 and the 13 are related, more Elements or features may be illustrated and explained with reference numerals than in the overview views of FIG 1 , 2 and the 13 . It can be assumed that these elements or features are also disclosed as belonging to the respective other overview view, even if they are not explicitly listed there or explained again in the description. This allows the characteristics of figs 1 to 12 and the figs 13 to 24 be combined accordingly. Furthermore, for the sake of clarity, only the features relevant to the following explanations have been given reference symbols. For example, in the 13 discloses a combustor ceiling 204 without being labeled with a reference numeral.

The biomass heating system 1 of 13 has a boiler 11, a combustion device 2 with a combustion chamber 24, a boiler foot 12 (this is provided at the bottom) and a movable ash container 79 for receiving the combustion residues conveyed out of the biomass heating system 1 by the ash discharge screw 71.

The arrow S indicates the side view of the biomass heating system 1, and the arrow V indicates the front view of the biomass heating system 1.

The biomass heating system 1 of 13 further has a heat exchanger 3 with turbulators 36, 37, which are arranged to be movable in the height direction or in the axial direction of the boiler tubes 32. Thus, the turbulators 36, 37 in the boiler tubes 32 can be moved back and forth.

Combustion residues are removed from the boiler tubes 32 by the movement of the turbulators 36, 37, mechanically detached from the walls of the boiler tubes 32, for example scraped off or detached by impact (more on this later). The combustion residues fall down into the conveyor area of the ash discharge screw 71, are collected there, and are in the 13 transported to the right out of the biomass heating system 1.

Furthermore, a filter device 4 is optionally provided, which has a (spray) electrode 45 and a (cleaning) cage 48 as a counter-electrode. The cage 48 is arranged in such a way that when it moves up and down it mechanically loosens the wall of the filter device, for example scrapes it off or releases it by impact (more on this later). Here, too, the combustion residues fall down through the filter inlet 44 into the conveying area of the ash discharge screw 71, are collected there, and are in the 13 transported to the right out of the biomass heating system 1.

To implement the functionality described above, an improved cleaning device 4 is provided, which is driven by a drive unit 72, preferably a single drive unit. For example, but not exclusively, the drive unit can be an electric motor 72 .

The electric motor 72 is provided as the sole drive for all components of the cleaning device 9 including the ash removal 7, which means that the present overall concept is structurally advantageous (space-saving, inexpensive, robust). The electric motor 72 can also be, for example, an electric motor with a gear that can provide more than three revolutions per minute with a torque of more than 50 Nm, preferably more than four revolutions per minute with a maximum torque of 100 Nm.

The electric motor 72 can also have an (internal or external) freewheel 73 . In particular, the transmission of the electric motor can be integrated with the freewheel 73 .

A crank element 77 (explained later) can preferably be mounted via an axle through the freewheel 73, for example a ball bearing freewheel. The axis can preferably correspond to the axis of the ash discharge screw 71, whereby the crank element 77 and the ash discharge screw 71 are driven together via the freewheel. In 15 the central axis of this common axis is denoted as axis of rotation 773 .

The freewheel can advantageously also be used for reverse travel of the ash discharge screw 71, which is required, for example, in the case of solid bodies jammed in the ash discharge screw 71, in order to remove the solid bodies.

In 13 a push member 74 is shown in section, which can be moved, among other things, by the electric motor 72 via a crank element 77 .

The electric motor 72 and other moving elements of the cleaning device 9 can be fixed or supported by immovable elements of the boiler 11, which are referred to collectively as the frame 76.

A sensor 75 is provided for detecting the movement or the position of the pushing member 74 .

the 14 shows a plan view of an exempt push member 74 of FIG 13 from the rear of the biomass heating system 1 the 13 . the 15 shows a plan view of the exempt pusher member 74 of FIG 14 from the rear of the biomass heating system 1 together with other parts of the biomass heating system 1 of the 13 .

First, for reasons of clarity, the thrust member 74 is explained as an individual part (cf. 14 ), with the functional explanation of the thrust member 74 then (cf. 15 ).

The thrust member 74 can be provided (roughly) in the form of a plate, with which in 14 a plan view of this plate-shaped element is shown. For example, the pushing member 74 can be made of a metal plate that is at least 5 mm thick, preferably at least 1 cm thick. In this case, the thrust element can be cut out as a solid plate, for example by means of a laser cutting process. Furthermore, the thrust member can be provided in one piece. The thrust member 74 is therefore correspondingly robust and can also withstand the corresponding forces acting in the processes and movements explained later.

The pushing member 74 has a special shape, as explained below. The thrust member 74 has two guide holes 742, which are provided as an elongated hole or slot. Alternatively, however, the thrust member (not shown) can also have only one or more than two guide holes. The lengthwise direction of the guide holes 742 may be horizontal with respect to installation of the pushing member 74 in the boiler 11 . Also, the length direction of the guide holes 742 may be provided in the lateral direction of the kettle 11.

The guide holes 742 are used to movably support the thrust member 74, which later with respect to 15 is explained in more detail.

Furthermore, the push member 74, preferably approximately or exactly in the middle in relation to the width extension of the push member 74, has an opening 741 for receiving a force-exerting element (will be explained later with reference to FIG 15 explained in more detail). The opening 741 is provided as an elongated opening with rounded ends.

In addition, the thrust member 74 has two pivot holes 743, preferably lever pivot holes 743. Alternatively, the thrust member 74 (not shown) can also have only one or more than two pivot holes. Here, the lengthwise direction of the pivot holes 743 with respect to the boiler 11 may be vertical.

A "hole" of the thrust member can be a hole completely surrounded by material, or for example a slot which is open at one end.

The thrust member 74 also has a stop 744, which will be explained in more detail later.

It should be noted that the length direction(s) of the guide holes 742 is preferably perpendicular to the length directions of the pin holes 753 .

This thrust member 74 serves as part of a (pulse-generating) transmission of the biomass heating system, with which the movement parameters of the individual parts of the cleaning device 9 can advantageously be changed or adjusted.

In particular, the rotational movement of the drive unit 72 with the thrust member 74 is converted into jerky or accelerated movements of cleaning elements of the biomass heating system 1, for example the cage 48, the turbulators 36, 37 and/or the impact lever 96.

This is discussed below with reference to the 15 explained in more detail, which illustrates the mechanical functions of the thrust member 74.

In 15 Shown are guide pins 711, which are used for the movable mounting of the thrust member 74. In 15 the guide pins 711 extend into or out of the plane of the paper. The guide pins 711 are provided in a stationary manner in or on the boiler 11 and, together with the guide holes 742, specify the freedom of movement of the thrust member 74. A movement of the guide pins 711 in the guide holes 742 (ie a movement of the guide holes 742 relative to the push member 74) is indicated by the two double arrows in the guide holes 742.

In 15 the thrust member can move back and forth in the direction of the double arrow HR. The thrust member 74 is therefore provided so that it can be displaced laterally in relation to the boiler 11 . The thrust member 74 is provided so that it can be displaced in a straight line.

In other words, the thrust member can be moved in a linear translational movement.

The possible length of the movement of the thrust member 74 is indicated by the double arrows FL, this length resulting from the length of the guide holes 742 results.

The movement is generated at least to a large extent in the thrust direction by the drive unit 72 (not shown), for example an electric motor, which drives a freewheel 73 (not shown) and a crank element 77 . The crank element 77 can be provided, for example, as a crank disk with a (e.g. rod-shaped) crank extension 771, or alternatively as a crank lever with a crank extension 771. The crank element 77 rotates or cranks about the axis of rotation 773 of the crank element 77.

The central axis of the crank extension 771 is in 15 perpendicular to the plane of the paper. Alternatively, the central axis can also be provided at a slight angle to the plane of the paper.

A roller 772 can optionally be provided on the crank extension 771 to reduce wear and for better running of the mechanism, with the roller 772 in 15 is shown in dashed lines

The crank extension 771 and the optional roller 772 protrude through the opening 741 of the push member 74 therethrough. In other words, the crank extension 771 moves in the opening 741 of the push member 74. The crank extension 771 or the roller 772 can rest against the edges of the opening 741. In the case shown here, the outside of the roller 772 rests against the inside edges of the opening 741 .

The effective radius of crank movement of the crank element 77 is indicated by the arrow RH starting from the axis of rotation 773 and the associated dashed line (i.e. this is the outer radius of the roller when the crank element 77 moves in a circle with the roller 772), with which the diameter of the Deflection by crank member 77 is twice the radius RH.

The direction of rotation of the crank element 77 is in 15 indicated by the arrow DR.

The length FL can be greater than or equal to the radius RH times two. The special geometry of the opening 741 (among others) can lead to the impulse effect of the present cleaning device.

In 15 A hexagon nut and a washer for fixing the roller 772 in the opening 741 of the push member 74 are shown but not specified in more detail.

The opening 741 has a width SB that is equal to or larger than the width of the pulley 772 or equal to or larger than the width of the crank extension 771 (without the pulley).

In 15 It is shown that the width SB (push element opening width SB) of the opening 741 is slightly larger than the diameter of the roller 771. This can preferably provide play to minimize locking.

Furthermore, the length LB (pusher opening length) of the opening 741 may be equal to or greater than twice the radius RH. In 15 it is shown that the length SB of the opening 741 is slightly larger than the diameter of the effective crank movement (= 2 x RH).

Thus, the crank member 77 and the opening 741 are provided such that the crank extension 771 and the roller 772 can move in the opening 741 to generate thrust, respectively. The course of movement is described in more detail with reference to the figures below, to which reference is made.

A damping element 78, for example a spiral spring or a rubber element, is also provided. The damping element 78 is attached to the boiler 11 with a damping element fixation 781 . The damping element fixation 781 is thus provided immovably. The damping element 78 is thus referring to 15 fixed on its left side.

A stop 744 for the damping element 78 is provided on the side of the thrust element 74 .

The damping element 78 essentially dampens or decelerates the movement or acceleration of the thrust member 74 in the direction of the impulse. This serves to minimize closure and to dampen noise. By means of the spring constant or the elasticity of the damping element 78, the kinetics of the thrust member and thus of the cleaning device 9 can also advantageously be adjusted. Thus, for example, the central axis of a spiral spring is provided as a damping element 78 at least largely parallel to the directions of movement HR of the thrust member 74 .

Based on the possibility of moving the pusher 74 back and forth in the directions of the double arrow HR, there are two elements that are moved or move with the pusher 74: the lever pin 922 of the lever 921. It should be noted that alternatively only one Element or lever pin 922 can be provided with a corresponding hole.

The lever pins 922 and the levers 921 are explained in more detail below.

In 15 the guide pins 711 are also the ends of the axes of the cleaning shafts 92, the cleaning shafts 92 and thus the guide pins 711 being mounted in the boiler 11 in a stationary manner. The levers 921 shown in phantom are attached to the cleaning shafts 92 and the cleaning shafts 92 can be rotated by means of the levers 921 and vice versa. The levers 921 can be designed in the form of rods, for example. The Levers 921 of 15 are also in 13 shown.

At the distal ends DE of the respective levers 921 are lever pins 922 which extend through the lever pin holes 743 . The lever pins 922 can move in the lever pin holes 743 in the direction of the double arrows (up and down) next to them.

The levers 921 can move in the respective angular range S based on a back and forth movement of the push member 74 . Thus, the fulcrum pins 922 move (ie, reciprocating movement of the pusher member 74) along the circular segment lines that are associated with the respective angle S in 15 are specified.

As a result, the axes of the cleaning shafts 92 rotate via the levers 921 as the pushing member 74 reciprocates. In this way, forces can be transmitted in both directions, i.e. from the thrust member 74 to the cleaning shafts 92 and vice versa.

The thrust member 74 is further alternately in the in 15 specified thrust direction and also in 15 moves back and forth in the direction indicated. This and the interaction of the crank element 77, the pusher member 74 and the cleaning shafts 92 is described below with reference to FIG Figures 16 to 23 explained.

This Figures 16 to 23 show a total of four states of the cleaning device 9, each with two consecutive figures. In detail:
the 16 shows a rear view of the biomass heating system 1 of 13 and thus the thrust member 74 of 14 and 15 in the larger context of the biomass heating system 1. 17 shows a corresponding oblique view from behind of the biomass heating system 1 of FIG 13 in the initial or idle state with a view of the biomass heating system 1.

18 shows a rear view of the biomass heating system 1 of 13 and the thrust member 74 of 14 and 15 in the overrun condition of the cleaning device 9. 19 shows a corresponding oblique view from behind of the biomass heating system 1 of FIG 13 in the overrun condition of the cleaning device 9 with a view of the biomass heating system 1.

20 shows a rear view of the biomass heating system 1 of 13 and the thrust member 74 of 14 and 15 in the maximum stroke state of the cleaning device 9. 21 shows a corresponding oblique view from behind of the biomass heating system 1 of FIG 13 in the overrun condition of the cleaning device 9 with a view of the biomass heating system 1.

22 shows a corresponding rear view of the biomass heating system 1 of FIG 13 and the thrust member 74 of 14 and 15 in the case of the cleaning device 9. 23 shows a corresponding oblique view from behind of the biomass heating system 1 of FIG 13 in the case of the cleaning device 9 with a view of the biomass heating system 1.

The same reference numbers in the Figures 1 to 24 and especially the Figures 13 to 23 disclose the same or technically identical features, which is why a redundant explanation of these features can be omitted in the following explanations.

It show the Figures 16 to 23 four states of the cleaning device 9, which are passed through in sequence when driven by the drive unit 72. In this respect, a method for cleaning a biomass heating system 1 with at least four steps is also disclosed, explained in more detail as follows:

(hibernation)

the figures 16 and 17 show the cleaning device 9 in an initial/resting state. In this state, the normal operation of the biomass heating system takes place without cleaning having to take place. In this respect, the cleaning device can also remain in this idle state for a longer period of time. This state is therefore also the initial state for a cleaning process or the present cleaning method.

In the initial state, the crank element 77 is in a first rotational position (also referred to as the initial position), which is in 16 is indicated schematically by the dot-dash line, which extends from the axis of rotation 773 of the Crank element 77 extends to the left. The guide pins 711 are located in the guide holes 742 on the right side of the 16 . The thrust member 74 is at least largely deflected in the impulse direction, ie viewed from the front in the direction of the right-hand side of the biomass heating system 1 .

The sensor 75, for example a magnetic/inductive sensor, can detect the presence of the thrust member 74 and transmit it to a control device (not shown), for example. The biomass heating system 1 can thus detect the presence of the idle state or the initial state.

In this case, the damping element 78 is compressed and rests against the stop for the damping element 744 . The two levers 921 are in a basic position.

Referring to 17 indicate the respective double arrows on the possible directions of movement of the individual cleaning elements. A cleaning element can be, for example, the cage 48 and/or a single turbulator or a plurality of turbulators 36, 37 and/or the impact lever 96.

In the initial state of the cleaning device, these cleaning elements are in a position in which the cleaning elements are arranged at the bottom, at least largely in relation to their vertical range of motion.

This bottom position is in 17 indicated with H1 by way of example in relation to the upper end of the turbulators. Likewise, the cage 48 is in a lower position. This position is relative to an upper end of the cage 48 in 17 also indicated by H1, the coincidence of the two heights of the cleaning elements being merely coincidental in the present case. The cage 48 and the turbulators 36 and 37 can generally also be arranged at different heights.

Thus the relative potential energy of the cleaning elements in the initial state is low or zero.

(shear condition)

the figures 18 and 19 show the cleaning device 9 in an overrun state. At the beginning of this state, a cleaning is started or continued. The drive unit 72 rotates the crank element 77 from its starting position or first crank rotational position (in short: first position) in the direction of rotation DR and thus pushes the thrust member 74 in the thrust direction (in 18 to the right, viewed from the front of the biomass heating system 1 to the left).

In the pushing state, the crank member 77 is between its initial position and that later with respect to FIG 20 explained self-running starting position of the crank element 77. In 18 one of these possible positions is indicated by way of example by the dot-dash line which extends downwards from the axis of rotation 773 of the crank element 77 .

The guide pins 711 are located in the guide holes 742 in a central area. The push member 74 is between the maximum left and maximum right deflection position.

The damping element 78 is thereby relaxed and can continue to bear against the stop for the damping element 744 at least during part of this state. In the damping element 78, in the present example a spiral spring, an optional damping element counter-stop 782 is also provided, which limits the maximum compression of the damping element 78 and limits the movement of the thrust member in the direction of the impulse.

The cleaning elements are raised in the pushing state via the two levers 921 and the cleaning shafts 92 due to the rotation of the crank element 77 and the resulting movement of the pushing member 74 in the pushing direction. In 19 this change in height is exemplified by a comparison of an exemplary height H2 in the overrun state with the height H1 in the initial state.

In this state, the height of the cleaning elements changes relatively evenly if the drive unit 72 is operated at a constant speed. This is fundamentally desirable since it reduces the wear on the drive unit 72 and also significantly reduces the complexity of the control of the drive unit.

In this way, the relative potential energy of the cleaning elements increases in the thrust state with the increasing advance of the thrust element 78 in the thrust direction or with the further rotation of the crank element 77.

In this state, the sensor 75 detects that the thrust member 74 is no longer in the initial state. Thus, a positive detection is possible that a cleaning of the biomass heating system is taking place.

(maximum stroke condition)

the figures 20 and 21 show the cleaning device 9 in a maximum stroke state.

The thrust member 74 is in the thrust direction, i. H. Viewed from the front in the direction of the left side of the biomass heating system 1, at least largely deflected.

In the maximum lift state, the greatest height deflection of the cleaning elements is also reached, as shown in FIG 21 with height H3 compared to height H1. The relative potential energy of the cleaning elements is maximum.

In the thrust state, the drive unit 72 had moved the thrust member up to a maximum deflection in the thrust direction, until the maximum stroke state of the cleaning device 9 is reached (in 20 the push element is located at maximum on the right, viewed from the front of the biomass heating system 1 at maximum on the left).

The guide pins 711 are located in the guide holes 742 of 20 on the left. Accordingly, the lever 922 are now compared to 16 deflected to the respective other side.

The damping element 78 is expanded and no longer touches the thrust member 74 .

The crank element 77 is in a further (second) predetermined crank rotational position (this can also be referred to as the self-running start position), which in 20 is indicated schematically by the dot-dash line extending from the axis of rotation 773 of the crank member 77 to the right.

When the crank element 77 is in the maximum stroke position and thus in the predetermined crank rotation position (self-running start position), the own weight of the cleaning elements presses the levers 94 (with which the cleaning elements are mounted on the cleaning shafts 92) downwards, thus generating torques on the cleaning shafts 92, which in turn results in a force or Moment at the distal ends of the lever 921 is passed on to the push member 74.

In short, the self-weight of the cleaning elements pushes the pushing member 74 in the direction of the impulse, this force being imparted via the levers of the cleaning shaft 92 .

If the crank element 77 now exceeds the predetermined crank rotational position in the maximum stroke state (cf. the dotted line in 20 ), the crank element 77 is no longer pressed in the opposite direction of rotation DR, but is moved in the direction of rotation DR by the push member 74 . This change is defined due to the geometry of the opening 741 and the position of the crank element 77 in relation to the opening 741 .

Since a freewheel 73 (or an overrunning clutch) is provided, the crank element 77 can yield to this pressure or the force exerted and continue to move in the direction of rotation DR independently of the drive unit.

Consequently, the pushing member 74 is pushed in the pushing state until it reaches the maximum stroke state and the self-running start position of the crank member 77 . Thereafter, the pushing member 74 pushes the crank element 77 further in the direction of rotation DR. The falling state, which will be described below, is thus reached.

(case state)

In the case state, which is in the figures 23 and 24 described, the cleaning elements "fall down" since the cleaning shaft 92 and the pushing element 74 offer no resistance to this downward movement due to the free-wheeling. As in 23 as can be seen from a comparison of the heights H4 with H3, the height (exemplified here only) decreases.

The mechanism of the cleaning device 9 thus begins to run automatically when the self-running start position of the crank element 77 is exceeded, i. i.e. it moves independently of the drive unit 72 in the falling state.

In 22 a rotational position of the crank element 77 is indicated schematically by the dot-dash line extending upwards from the axis of rotation 773 of the crank element 77 . In this case, the crank element 77 in the falling state covers the rotation range from the self-running starting position or second crank rotation position (in short: second position) to the previously described starting position or first position. The thrust member moves in 22 in the direction of momentum, ie, to the left.

The fall state includes a relatively free fall of the cleaning elements, which is only slowed down somewhat by various frictional influences (for example the friction of the cleaning shaft 92 in its bearings or the friction of the turbulators in the boiler tubes 32). A certain moment of inertia of the thrust member 32 also comes into play, but this is just as slight.

Consequently, the cleaning elements in the fall state (after exceeding the Self-running start position) greatly accelerated. The previously gained potential energy of the cleaning elements is converted into kinetic energy. The magnitude of the acceleration can advantageously be adjusted with the damping element 78, for example with the spring constant of a spiral spring or an oil pressure cylinder, as required by the specific application according to the weight of the cleaning elements and the kinetics of the mechanics of the cleaning device.

The acceleration process of the cleaning elements and also of the pushing element 74 in the falling state improves the cleaning effects in the boiler 11 considerably. The various mechanical cleaning effects are also improved due to the resulting increased speed. For example, the impact lever 96, which is also actuated via the cleaning shafts 92, strikes the discharge electrode of the electrostatic precipitator 45 more quickly. Likewise, a faster movement of the turbulators in the heat exchanger leads to a better effect of breaking up more solid caking or adhesions.

At the end of the fall state, the thrust member 74 is again at least largely on the left side of the 22 , and the cleaning elements are again at least approximately at the height of H1 16 and 22 .

At the end of the fall state, the thrust member 74 can also strike the damping element counter-stop 782 with its stop 744 . This results in an impact into the boiler 11 and the fall is intercepted.

Alternatively, the damping element 78 can also be maximally compressed to end the falling state. In this respect, a damping element counter-stop 782 is not absolutely necessary. However, the damping element counter-stop 782 can ensure that a damping element 78 is not subjected to excessive loads and, under certain circumstances, is subjected to excessive wear. In the case of a spiral spring, for example, without a damping element counter-stop 782, the spiral spring could be over-compressed with resulting spring breakage.

When the thrust member 74 strikes and the resulting spontaneous deceleration of the cleaning element occurs, a shock is generated in the mechanics of the cleaning device 9, which can sometimes turn out to be violent.

To clarify: If, for example, a cleaning element (e.g. the turbulators) falls unchecked by 10 cm, the cleaning element has a final speed of roughly 1.4 m/s when the stop 744 hits the counter-stop 782.

Assuming, for example, that this cleaning element has a weight of 30 kg, then the cleaning element has a kinetic energy of roughly 29.4 joules at the end of the fall, which is to be evaluated as the energy of a single impact.

The entire mechanism of the cleaning device 9 is thus subjected to a strong shock, which can also be released into the boiler 11 via the stops.

As a result of the rapid deceleration, the cleaning device 9 consequently produces a shaking effect which conventional linearly operating cleaning devices do not produce.

The cleaning device 9 described above thus results in an improved cleaning effect, since more solid caking or heavy buildup of combustion residues in the boiler can be detached. If the combustion residues are now better cleaned off, the efficiency of the boiler 11 is improved and the emissions are reduced.

In addition, the volume of the cleaning is advantageously reduced by the damping element.

(alternative push element)

24 discloses another pusher member 74 having an alternative shape the opening 741. The further thrust member 74 is integrated in the same way in the biomass heating system 1, as the thrust member 74 of Figures 13 to 23 . Reference is therefore made to the above explanations, which also with the thrust member 74 of 24 can be realized. The individual states of the thrust member 74 of Figures 13 to 23 correspond to those of 14 .

The crank element 771 is located in the 24 in the starting position.

The opening 741 has a step 745 on the right side. This step 745 is arranged such that the crank extension 771 or the roller 771 is moved over the step 745 at the end of the pushing state (at the maximum stroke state), and the pushing member 74 is jerked in the impulse direction. An even greater acceleration is thus generated during the transition to the falling state, since the thrust element 74 is not initially pushed against the inertia of the freewheel.

In addition, in the further push element 24 no damping element available. In this respect, the movement in the direction of the pulse is unbraked. A stop at the end of the fall state can alternatively to the stop of 15 onto the guide pins at the ends of the guide holes. In this respect, a defined deceleration at the end of the fall can also be generated here.

It takes place with the thrust member 74 of 24 advantageously an increased double acceleration, once at the beginning of the fall state and once at the end, which further improves the shaking effect with regard to the impurities. However, the thrust member 74 also arrives Figures 13 to 23 quite quickly from the maximum lift state to the fall state, since a freewheel, in particular a ball bearing freewheel, can be implemented almost without inertia.

The opening 741 is presently provided in an approximately L-shape. However, alternative shapes of the opening 741 are also conceivable.

The advantages of the additional push element 24 continue to correspond to those of Thrust member 74 of Figures 13 to 23 .

(Modularization of plant and boiler components)

The biomass heating system 1 is preferably designed in such a way that the entire drive mechanism in the lower boiler area (including rotary grate mechanism including rotary grate, heat exchanger cleaning mechanism, drive mechanism for moving floor, mechanism for filter device, cleaning basket and drive shafts and ash discharge screw) can be quickly and efficiently removed and removed again using the "drawer principle". can be used. This facilitates maintenance work.

(Further embodiments)

In addition to the explained embodiments and aspects, the invention permits further design principles. Thus, individual features of the various embodiments and aspects can also be combined with one another as desired, as long as this is apparent to the person skilled in the art.

Although two guide holes 742 are provided with two guide pins 711, only one guide hole 742 with two guide pins 711 may be provided, for example. Alternatively, three guide holes 742 with three guide pins can also be provided. In this respect, the number of guide holes is not limited to two. The same applies to the peg holes 743.

Although two cleaning shafts 92 with two levers 921 are disclosed, there can also be a different number of cleaning shafts 92 and levers 921, for example one or three.

Although several cleaning elements are disclosed by way of example, it is also sufficient that only a single cleaning element is provided.

Furthermore, instead of only three rotary grate elements 252, 253 and 254, two, four or more rotary grate elements can also be provided. With five rotary grate elements, for example, these could be arranged with the same symmetry and functionality as with the three rotary grate elements presented. In addition, the rotary grate elements can also be shaped or designed differently from one another. More rotary grate elements have the advantage that the crushing function is increased.

With regard to the specified dimensions, it should be noted that other dimensions or combinations of dimensions can also be provided that deviate from these.

Instead of the convex sides of the rotary grate elements 252 and 254, concave sides of these can also be provided, in which case the sides of the rotary grate element 253 can be shaped in a complementary convex manner. This is functionally almost equivalent.

Although, for example, 10 (ten) secondary air nozzles 291 are disclosed, a different number of secondary air nozzles 291 can also be provided (depending on the dimensioning of the biomass heating system).

The rotational flow or turbulent flow in the combustion chamber 24 can be clockwise or counterclockwise.

The combustion chamber cover 204 can also be provided with an incline in sections, for example in a stepped manner.

The secondary air nozzles 291 are not limited to purely cylindrical bores in the combustion chamber bricks 291 . These can also be designed as frustoconical openings or tapered openings.

The secondary (re)circulation can also only be flown with secondary air or fresh air, and in this respect not recirculate the flue gas, but only supply fresh air.

The dimensions and numbers given in relation to the exemplary embodiments are to be understood only as examples. This technical teaching disclosed here is not limited to these dimensions and can be modified, for example, by modifying the dimensioning of the boiler 11 (kW).

Fuels other than wood chips or pellets can also be used as fuels in the biomass heating system.

The biomass heating system disclosed here can also be fired exclusively with one type of fuel, for example only with pellets.

The embodiments disclosed herein were provided for description and understanding of the disclosed technical matters and are not intended to limit the scope of the present disclosure.

(Reference List)

1

Biomass heating system

11

boiler

12

boiler foot

13

boiler housing

14

water circulation device

2

burner

21

first maintenance opening for burner

22

rotary mechanism mount

23

turning mechanism

24

combustion chamber

25

rotary grate

26

Primary combustion zone of the combustor

27

Secondary combustion zone or radiant part of the combustion chamber

28

fuel bed

29

combustion chamber bricks

A1

first horizontal cutting line

A2

first vertical section line and vertical central axis of the oval combustion chamber 24

201

ignition device

202

combustion chamber slope

203

combustor nozzle

204

combustor ceiling

231

Drive or motor(s) of the turning mechanism

251

bottom plate of the rotary grate

252

First rotary grate element

253

Second rotary grate element

254

Third rotary grate element

255

transition element

256

openings

257

rust lips

258

burn surface

260

Support surfaces of the combustion chamber bricks

261

groove

262

head Start

263

ring

264

bracket stones

265

slope of the support stones

3

heat exchanger

31

Maintenance opening for heat exchanger

32

boiler tubes

33

Boiler tube entry

34

reversing chamber entry

35

turning chamber

36

spring turbulator

37

Band or spiral turbulator

38

heat exchange medium

4

filter device

41

exhaust outlet

42

electrode supply line

43

electrode holder

44

filter inlet

45

electrode

46

electrode insulation

47

filter outlet

48

Cage

5

recirculation device

51, 54

Recirculation channel / recirculation channels

52

Succeed

53

recirculation entry

6

fuel supply

61

rotary valve

62

Fuel supply axis

63

translation mechanics

64

fuel supply channel

65

fuel supply opening

66

drive motor

67

fuel auger

7

ash removal

71

ash discharge screw

72

drive unit

73

freewheel

74

thrust link

75

sensor

76

frame

77

crank element

78

damping element

79

ash container

81

bearing axles

82

axis of rotation

83

fuel level flap

96

hammer

831

main surface

832

center axis

835

surface parallel

84

bearing notch

85

sensor flange

86

Ember bed height measurement mechanism

9

cleaning device

91

cleaning drive

92

cleaning shafts

93

shaft mount

94

extension

95

turbulator mounts

951

Pivot bearing mount

952

appendages

953

culverts

954

recesses

955

pivot linkage

96

two-armed hammer

97

stop head

204

combustor ceiling

211

Insulating material such as vermiculite

291

Secondary air or recirculation nozzles

E

insertion direction of the fuel

331

Insulation at the boiler tube inlet

481

cage mount

711

Guide pin and axis of the cleaning shafts 92

721

axis

722

connection unit

723

gear and/or freewheel

741

Opening of the pusher

742

guide hole

743

lever pivot hole

744

Stop for the damping element

745

Step

771

crank extension

772

roller

773

Axis of rotation of the crank element

774

predetermined crank rotation position

781

damping element fixation

782

Damping element counter stop

S

lever angle

RH

(Effective) radius of the lever

DR

direction of rotation

MR

directions of reciprocation

SB

slot width

FL

pilot hole length

FG

Weight force on the thrust member

SB

push link opening width

LB

push link opening length

921

lever

922

hepel cone

EN

distal end of lever

H1

Altitude at rest

H2

further altitude in the overrun condition

H3

further altitude during the transition to the fall state

H4

further height in fall

Claims (21)

1. Biomass heating system (1) for the combustion of fuel in the form of pellets and/or chips, possessing:

   a boiler (11) with a combustion unit (2),

   a heat exchanger (3) with a plurality of boiler tubes (32),

   a cleaning device (9) that comprises the following:

   a drive unit (72) for driving the cleaning device (9),

   the biomass heating system (1) characterised in that the cleaning device (9) further possesses the following:

   a crank element (77) that is coupled to the drive unit (72) through a freewheel (73), wherein the drive unit can drive the crank element in a rotational direction (DR),

   a thrust member (74) that is able to move back and forth and is coupled to the crank element (77);

   at least one cleaning shaft (92) that is operatively coupled to the thrust member (74),

   at least one cleaning element (36, 37, 48, 96) arranged to be operatively connected to the cleaning shaft (92);

   wherein the cleaning device (9) is configured such that

   by rotating the crank member in the rotational direction (DR) the thrust member (74) is displaced in a thrust direction by the drive unit; and

   after exceeding a predetermined crank rotation position of the crank member (77), the thrust member (74) is displaced in an impulse direction opposite to the thrust direction.
2. Biomass heating system (1) according to claim 1, wherein the cleaning device (9) is configured in such a way that
   the movement of the thrust member (74) in the impulse direction is not effected by the drive unit (72).
3. Biomass heating system (1) according to one of the preceding claims, wherein the cleaning device (9) is configured in such a way that
   the movement of the thrust member (74) in the impulse direction is effected by the torque of the cleaning shaft (92).
4. Biomass heating system (1) according to one of the preceding claims, wherein

   at least one cleaning element (36, 37, 48, 96) is raised by the rotation of the crank element until the predetermined crank rotational position is reached, and

   at least one cleaning element (36, 37, 48, 96) is accelerated or abruptly dropped due to the dead weight of the at least one cleaning element after the predetermined crank rotational position has been exceeded.
5. Biomass heating system (1) according to one of the preceding claims, wherein the cleaning device (9) is configured such that the movement of the thrust member (74) in the thrust direction occurs at least approximately uniformly.
6. Biomass heating system (1) according to one of the preceding claims, wherein the cleaning device (9) is configured in such a way that
   the movement of the thrust member (74) in the impulse direction is accelerated.
7. Biomass heating system (1) according to one of the preceding claims, wherein
   the thrust member (74) has an opening (741) for a crank extension (771) of the crank element (77).
8. Biomass heating system (1) according to one of the preceding claims, wherein
   to moveably guide the thrust member (74), the thrust member (74) possesses at least one elongated guide hole (742) for receiving at least one guide pin (711).
9. Biomass heating system (1) according to one of the preceding claims, wherein
   the thrust member (74) is arranged to be moveable back and forth in a linear manner.
10. Biomass heating system (1) according to one of the preceding claims, wherein the at least

    one cleaning shaft (92) possesses a lever (921) with a lever pin (922) at a distal end (DE) of the lever with respect to the cleaning shaft (92); and

    the thrust member (74) possesses at least one elongated lever pin hole (743) to moveably receive the lever pin (743).
11. Biomass heating system (1) according to one of the preceding claims, wherein
    the at least one cleaning element (36, 37, 48, 96) is at least one turbulator (36, 37), preferably a spiral turbulator (36) and/or a belt turbulator (37), which is or are provided in at least one boiler tube (32) of the heat exchanger (3).
12. Biomass heating system (1) according to one of the preceding claims, wherein

    the cleaning device (9) is configured such that

    the freewheeling (73) transmits the torque of the motor (72) in the rotational direction (DR) of the crank element (77); and

    when the predetermined crank rotational position of the crank element (77) is exceeded the freewheeling releases a further rotation of the crank element (77) in the rotational direction (DR).
13. Biomass heating system (1) according to one of the preceding claims, wherein
    the thrust member (74) possesses a stop (744) as an end stop for the movement in the impulse direction.
14. Biomass heating system (1) according to one of the preceding claims, wherein
    an opening (741) of the thrust member (74) is provided for receiving a roller (772) of the crank extension (771).
15. Biomass heating system (1) according to one of the preceding claims, wherein
    the opening (741) of the thrust member (74) possesses a step (745) that is surpassed by the roller (772) upon reaching the predetermined crank rotation position.
16. Biomass heating system (1) according to one of the preceding claims, further possessing:
    a damping element (78), preferably a spring, which is arranged such that the damping element (78) damps the movement of the thrust member (74) in the thrust direction.
17. Biomass heating system (1) according to one of the preceding claims, wherein
    a contraction and expansion direction of the damping element (78) is provided at least approximately parallel to the reciprocating direction of the damping element (78).
18. Biomass heating system (1) according to one of the preceding claims, wherein the thrust member (74) is provided in a plate-shaped form, and/or wherein
    one end of the at least one cleaning shaft (92) serves as a guide pin (711) to be introduced into the elongated guide hole (742).
19. Biomass heating system (1) according to one of the preceding claims, further possessing:

    an electrostatic filter device (4) with a spray electrode and a cleaning cage as the counter electrode, wherein

    the cleaning element is a rocking lever (96); and wherein

    the rocking lever is operatively connected to the cleaning shaft (92) and is arranged such that during the jerky rotation of the cleaning shaft (92) the rocking lever strikes against the spray electrode to clean it.
20. Biomass heating system (1) according to one of the preceding claims, wherein
    a sensor (75), for example an inductive position switch, is provided for detecting the position or the end position of the thrust member (74).
21. Biomass heating system (1) according to one of the preceding claims, wherein
    an ash discharge screw (71) of the biomass heating system (1) is also driven by the drive unit (72).

Images