EP3343106A1 - Primary withdrawal with sweeping cyclone cavity - Google Patents

Abstract

In order to achieve optimal combustion with optimally low particulate matter in a solid fuel heater with combustion chamber and Nachbrennkammer, the primary extraction of the flue gases from the combustion chamber is optimized in the afterburner and simplified by choosing the appropriate shape of the hollow sections (2), between which the primary pullout takes place, in particular to improve the formation of sweeping vortices of the gases flowing through the back of the hollow sections (2).

Description

I. Field of application

The invention relates to a solid fuel heater such as wood, and more particularly to the primary exhaust of the flue gases from the primary combustion chamber to a downstream afterburner.

II . Technical background

• In der primären Brennkammer wird zwar ein Großteil des festen Brennstoffes verbrannt, jedoch enthalten die dort entstehenden Rauchgase noch einen großen Anteil an kohlenstoffhaltigem, brennbarem Gas, welches noch verwertbar ist. Deshalb werden die Rauchgase einer Nachbrennkammer zugeführt und dort - mit zusätzlich zugeführter Verbrennungsluft, der Sekundärluft - nachverbrannt, um die Ausnutzung des Brennstoffes und damit die Effizienz der Heizvorrichtung zu erhöhen.

It is known to carry out a multi-stage combustion of solid fuels such as wood:

• In the primary combustion chamber, although a large part of the solid fuel is burned, but the resulting flue gases still contain a large proportion of carbon-containing, combustible gas, which is still recyclable. Therefore, the flue gases are fed to a secondary combustion chamber and there - with additionally supplied combustion air, the secondary air - afterburning to increase the utilization of the fuel and thus the efficiency of the heater.

It is also known in the primary exhaust of the flue gases from the primary combustion chamber to the afterburner to allow the flue gases to flow through a nozzle assembly while the secondary air, ie the additional necessary combustion air to supply - possibly also additionally recirculated flue gas, - whereby a good mixing of Flue gases with the secondary air and thus a very complete combustion of the combustible components in the flue gas takes place in the afterburner.

Thus, the primary train often consists of a kind of rust - even if it is vertical, since the flow direction in the primary train runs horizontally - from adjacent juxtaposed hollow sections, through the interior of the secondary air is supplied and discharged through outlet openings in the passages between the hollow sections. These passages are Favor by the increasing in the flow direction cross sections of the hollow bodies narrowing passages and act as a nozzle, so that the acceleration of the flue gases sucking in the secondary air without additional fan or the like automatically sucks into the flue gas stream.

• Die Strömungsgeschwindigkeit sollte möglichst hoch sein, um aus den Austrittsöffnungen der Hohlprofile möglichst viel Sekundärluft selbsttätig anzusaugen.

The flow velocity of the gas mixture in the passage is a very critical quantity:

• The flow rate should be as high as possible to automatically suck as much secondary air from the outlet openings of the hollow sections.

On the other hand, the flow rate must not exceed a certain limit, otherwise the flame passing through the primary exhaust tearing off the flame, and thus the combustion in the afterburner is first interrupted, usually a short time later by deflagration is set in motion, what to avoid applies.

• Die Menge an Brenngas hängt natürlich zum einen ab von der Menge an eingebrachtem Holz, aber darüber hinaus von anderen Faktoren, beispielsweise ob sich der Brennstoff gerade am Beginn der Verbrennung befindet und die Temperatur im Steigen begriffen ist, denn in dieser Phase werden in der Regel mehr Gase pro Zeiteinheit abgegeben als bei einem bereits vollständig glühenden Brennstoff.

In this case, the critical flow rate at which flame separation occurs depends on the temperature of the flame, and the overall flow rate depends, inter alia, on the amount of combustion gases produced in the main combustion chamber:

• The amount of fuel gas depends, of course, on the one hand on the amount of wood introduced, but also on other factors, such as whether the fuel is just at the beginning of the combustion and the temperature is rising, because in this phase are usually more gases released per unit of time than with a completely glowing fuel.

• So gibt Scheitholz am Anfang mehr Brenngas frei als beispielsweise die stark gepressten Pellets. Die nicht gepressten Hackschnitzel liegen hier etwa in der Mitte.

The type of fuel also influences the gas evolution:

• Thus, firewood releases more fuel gas at the beginning than, for example, the heavily pressed pellets. The unpressed wood chips are here about in the middle.

Also already known, for example, from the DE 4435794 C2 in that the side walls, extending in the direction of flow, of these hollow profiles have an extension towards the rear, at least over the regions of the back plate lying furthest to the front.

This extension causes a sweeping vortex of the flowing gas mixture to be established on the rear side of the hollow profile near the projections. The laminar gases flowing through the nozzle arrangement are thereby swirled, so that in this case a particularly good mixing of the gas components, ie the flue gases with the secondary air, occurs, which improves the completeness of the afterburning.

The most complete afterburning of both the gaseous combustible constituents and the partially invisible small solid constituents in the flue gases is not only necessary in terms of increasing efficiency, but rather depends very much on the fine dust content of the exhaust gas ultimately escaping the heater.

Since the regulations for the fine dust content of such solid fuel heaters are constantly tightened, the fines content is becoming an ever-increasing problem due to its harmful effects.

At the same time, however, there can be no optimal heating device and no optimal primary extraction, with the generally optimal complete combustion and optimal low particulate matter content is achieved, because here play many parameters such as type of fuel, its moisture content, amount of primary air and secondary air, strength of by the chimney generated negative pressure, altitude of the burning device, there prevailing weather conditions, etc. a role, so that the heater and in particular the primary shred must be individually adapted to these conditions to optimum combustion, so an optimally low fines content and optimal high efficiency , to reach.

III . Presentation of the invention a) Technical task

It is therefore the object of the invention to provide a heater and in particular a simple and inexpensive primary extract and optionally a method for setting such a primary extraction available, which allows depending on the specific conditions of use of the heater optimizing the combustion.

b) Solution of the task

This object is solved by the features of claims 1 and 16. Advantageous embodiments will be apparent from the dependent claims.

A generic primary extraction of a solid fuel heater has a plurality of hollow profiles which are spaced from one another transversely to their directions, which are preferably parallel to one another.

By the at least one clear passage between two adjacent hollow sections, the flue gases pass through, wherein they are accelerated because the clear passage between the adjacent hollow sections represents a narrowing of the previous total flow cross-section and these clear passages act as nozzle slots.

In this case, the flue gases secondary air or recirculated flue gas is added, which are introduced into the hollow sections, and discharged through outlet openings, which are arranged in the circumference of the hollow profile, preferably at the location of the nozzle slot, so the clear passage to the flowing flue gases.

With regard to the primary extraction , the object is achieved by approaching the outer surfaces of the hollow profiles of the flow in the direction of flow in which the flue gases flow through the passage, widest point of the hollow profiles towards each other towards the rear, thus approaching the longitudinal center plane of the hollow profile extending in the flow direction and each end in a spoiler edge.

In this case, the two Abrisskanten in the transverse direction may have a smaller, equal or greater distance than the largest width of the outer periphery of the hollow profile.

The back plate which connects the two tear-off edges and forms the rear part of the hollow profile, which as a rule is in one piece, has a concave outer contour.

Preferably, the hollow profiles are formed symmetrically to their longitudinal center plane, which includes the extension direction. If the hollow sections are installed in a primary pullout, the flow direction of the flue gases flowing through the primary pullout is in or parallel to this longitudinal center plane.

By - at least initially - mutual approximation of the outer surfaces of the hollow sections in their rear region and the ends in a trailing edge is considered the passage through a nozzle, ie between two obstacles, fluidic always present tendency to form sweeping vortices on the back of the obstacle - in the direction of the hollow section - promoted, and this sweeping are thereby selectively formed, in particular by the shape of the outer surfaces in the rear region of the hollow section, which is why this preferably curved convex convex, as this works better than a flat course.

The formation of sweeping vortices is further promoted by the concave back of the hollow profile, so the concave outer contour of the back plate, which forms the rear part of the hollow profile yes.

The best possible expression and stable shape of such Kehrwirbel in the operation of the primary shred ensures a long residence time of the flue gases in the sweeping vortex and thus a very good mixing of the primary pulp passing flue gases with the other in the primary feed gas supplied, usually secondary air, for the optimization of the afterburning. As a result, the completeness of the combustion is increased and at the same time the number of particles present in the flue gases, in particular of particulate matter, is reduced.

It can be determined by the variation of the distance and / or the shape of the two separation edges from each other, and in particular the size of the lateral projection over the widest point of the hollow profile, the type of turbulence and the expression of the forming Kehrwirbel.

The supply of secondary air or recirculated flue gases in the hollow sections is preferably carried out via one of the end faces in the hollow profile.

The other end face is of course then tightly closed, so that the hollow sections have only one inlet opening for the secondary air and the outlet openings, usually a plurality of in the extension direction of the hollow profile on both sides arranged in the side surfaces outlet openings.

In the flow direction, these outlet openings are preferably arranged before or at the latest at the widest point of the outer contour.

Another variant is to arrange them in the back plate, which, however, experience has shown that this is not quite as efficient.

For the optimum formation of the sweeping vortices, the shaping of the trailing edge is of great importance: Preferably, this is V-shaped in cross-section, thus forming a kind of cutting edge in which the edge radius considered in the direction of the hollow profile and therefore also the trailing edge is less than 2 mm is better than less than 1 mm, better less than 0.5 mm, better less than 0.3 mm, better less than 0.2 mm.

The cutting angle, ie the angle of the V-shaped trailing edge viewed in cross-section, should be acute, preferably less than 85 °, more preferably less than 80 °, better less than 75 °, better still less than 35 °, better still less than 30 °.

It is also important that the back, so the outer surface of the back plate passes into this designed as a cutting edge and the outer contour without paragraph and no kink, which is already understood as a kink, if there is a transition with a radius of curvature, ie Knick radius, of more than 2 mm, even more than 4 mm, especially with more than 6 mm, there.

Also, the curvature or bending of the concave outer surface of the backplate obviously plays an important role. Preferably, their radius of curvature should be in absolute values between 0.5 cm and 5 cm, better between 0.8 cm and 4 cm, better between 1.0 cm and 3 cm, better between 1.3 cm and 2.5 cm, better between 1.4 cm and 2.0 cm.

In relation to the pipe diameter, if the hollow section is a pipe having a circular cross section, the radius of curvature of the outer surface of the concave back plate should not exceed 40%, better still not more than 30%, better not more than 20% of the average radius of curvature of the outer contour of the hollow profile deviate and / or deviates in a tubular profile with circular cross-section of the radius of curvature of the concave curvature of the radius of curvature of the outer contour of the tubular profile by not more than 20%, preferably not more than 10%, preferably not more than 5%.

The distance between the two trailing edges of a hollow profile is important, because this is to encourage the formation of two adjacent sweeping vortices, without these interfering with each other too much.

Therefore, the distance between 30% and 60%, better between 35% and 55%, better between 40% and 50% of the greatest width of the outer contour of the hollow section, in particular the outer diameter of the hollow tube formed as a round tube measured in the transverse direction, amount.

However, it may also be equal to or greater than the greatest width of the outer contour of the hollow profile, but preferably by not more than 10%, better still not more than 20%, better not more than 30%.

These values, especially a combination of these values, has surprisingly proven to be very effective in practice.

A very simple method, a hollow profile at least in its relevant for the mixing of gases mean length range - at the ends of the hollow sections is usually a support to a surrounding structure - produce, it is - in particular, if the hollow profile has a circular cross-section - a to be separated in the direction of the hollow profile extending segment strip of the hollow profile out of this, and with its inside out again in the resulting recess to re-use, and in particular to tightly fasten, preferably to be welded.

Then, the desired concave outer surface of the back plate is thereby created and the connecting portions between the outer edges of the inserted segment strip and the end edges of the remaining pipe cross-section can be formed as described above as a blade-shaped trailing edge.

In this design, the gap between the front and rear ends of the reversed segment strip and the inner circumference of the pipe course, also tightly closed by a tightly inserted there, preferably welded, sealing part, or by a corresponding deformation of the segment strip at the front ends. Preferably, such a hollow profile is integrally formed.

• Ein solches zweiteiliges Hohlprofil besteht aus einem Frontteil, welches ein im Querschnitt geschlossenes, vorzugsweise einstückiges, Hohlprofil bildet, und einem an der Rückseite, also der Rückenplatte dieses Frontteiles, lösbar befestigten und vorzugsweise einstellbaren Steuerprofil, welches vorzugsweise aus zwei Profil-Teilen besteht:
  • Jedes Profil-Teil ist vorzugsweise ein sich in Verlaufsrichtung des Hohlprofiles erstrecken des Winkelprofil, wobei ein Schenkel des Winkels entlang der Außenfläche der Rückenplatte verläuft und teilweise an dieser anliegt, und an dessen äußeren Ende der andere Schenkel ansetzt.

A better adaptation to the particular application, however, allows a two-part design, although this is the construction cost significantly higher:

• Such a two-part hollow profile consists of a front part, which forms a cross-sectionally closed, preferably one-piece, hollow profile, and one on the back, so the back plate of this front part, solvable attached and preferably adjustable control profile, which preferably consists of two profile parts:
  • Each profile part is preferably a extending in the direction of the hollow section of the angle section, wherein a leg of the angle along the outer surface of the back plate extends and partially rests against this, and at the outer end of the other leg attaches.

The other leg has at its free end edge on the spoiler for the flowing air, and this other leg forms an extension of the outer contour of the cross section of the front part to the rear.

The outer contour of this leg extending the front part is preferably in turn concavely curved.

This angled control profile is preferably located only in a region of the extension of the cross section of the first, running along the back plate leg on the back plate, and can be pivoted by suitable means, such as a set screw relative to this system, whereby the angular position of the other Leg is pivoted and in particular the position of the tear-off edge formed thereon is changed to the front part.

In this case, the front part in its extension direction spaced and have protruding projections in the longitudinal direction, which protrude backwards beyond the back plate, and engage in corresponding recesses of the control plate for the guidance to guide the control profile.

With regard to a heating device, this object is achieved by the primary extraction between the combustion chamber and a Nachbrennraum this Heating device is arranged, and the primary pullout is configured as described above one.

Preferably, the primary train has a plurality of rows of flow paths adjacent to each other in the flow direction, wherein the rows are arranged so that viewed in the flow direction, the hollow profiles of one row transverse to the hollow profiles of the adjacent series of hollow profiles, ie viewed in the flow direction Grid made of hollow profiles is visible.

c) embodiments

Fig. 1:

eine Heizvorrichtung nach dem Stand der Technik,

Fig. 2:

einen Primärabzug, teilweise mit Hohlprofilen nach dem Stand der Technik,

Fig. 3a:

ein erfindungsgemäßes erstes Hohlprofil im Querschnitt,

Fig. 3b:

ein erfindungsgemäßes zweites Hohlprofil im Querschnitt,

Fig. 3c:

ein erfindungsgemäßes drittes Hohlprofil im Querschnitt,

Fig. 3d:

ein erfindungsgemäßes viertes Hohlprofil im Querschnitt,

Fig. 4:

das Hohlprofil der Figur 3a in Seitenansicht,

Fig. 5:

eine zweiteilige Bauform eines Hohlprofiles,

Fig. 6a:

einen vollständigen Primärabzug mit Hohlprofilen gemäß der Figur 3, geschnitten in Strömungsrichtung und

Fig. 6b:

den Primärabzug der Figur 6a betrachtet in Strömungsrichtung.

Embodiments according to the invention are described in more detail below by way of example. Show it:

Fig. 1:

a heating device according to the prior art,

Fig. 2:

a primary train, partly with hollow sections according to the prior art,

Fig. 3a:

a first hollow profile according to the invention in cross section,

3b:

a second hollow profile according to the invention in cross-section,

3c:

a third hollow profile according to the invention in cross section,

Fig. 3d:

a fourth hollow profile according to the invention in cross-section,

4:

the hollow profile of FIG. 3a in side view,

Fig. 5:

a two-part design of a hollow profile,

6a:

a complete primary with hollow sections according to the FIG. 3 , cut in the flow direction and

Fig. 6b:

the primary expulsion of FIG. 6a considered in the flow direction.

• Dabei wird Brennmaterial, beispielsweise Holzscheite, auf dem Boden eines Brennraumes 20 liegend verbrannt.

The FIG. 1 shows in the sectional side view a known heater:

• In this case, fuel, such as logs, burned lying on the floor of a combustion chamber 20.

In the front surface of the housing of the combustion chamber 20 there is a combustion chamber flap 22 which can be raised upwards, actuated by a manual control 25, which in this case is coupled to a direct exhaust flap 16 in the ceiling of the combustion chamber 20, which is normally closed and only when the combustion chamber flap 22 is opened, it is also open to allow the flue gases 14 to be drawn off directly into the chimney 26 via the ceiling of the combustion chamber 20.

In the normal case, however, ie with the combustion chamber flap 22 closed, the flue gases 14 from the combustion chamber 20 through a primary 1 pull horizontally, preferably to the rear, in the Nachbrennraum 21 and thereby be supplied with additional combustion air or via a Rezirkulationsweg 15 from the combustion chamber 20 or over Recirculation openings 23 from the afterburner 21 with recirculated flue gas added to optimize the afterburning.

This is done by the primary pullout 1 consists of superposed in this case, horizontally extending, hollow sections 2, between which light passages 3 are present, which narrow in the flow direction 10 and act as nozzle slots.

Via outlet openings 4 in the hollow sections 2 secondary air is discharged into these passages 3 and thus mixed with the flowing from the combustion chamber 20 flue gases 14.

The flue gases afterburned in this way in the afterburning space 21 leave the heating device in the direction of the chimney 26, wherein the chimney effect can be regulated by a regulation flap 18 arranged at the end of the afterburning space 21.

In the afterburner 21, the rear wall is further formed as a liquid-flowed heat exchanger 27, which is irrelevant to the present invention.

• Figur 2 zeigt eine Schnittdarstellung durch einen Teil eines Primärabzuges 1 bestehend aus beispielhaft drei nebeneinander angeordneten Hohlprofilen 2, deren Querschnitt in dieser bekannten Bauform (die rechten beiden Hohlprofile 2) etwa A-förmig ist, so dass sich die Durchlässe 3 dazwischen in Strömungsrichtung 10 verjüngen und als Düsenschlitze wirken.

The invention is based on - consisting of superimposed or juxtaposed - hollow sections 2 primary shred 1, which is shown in detail or in part in the following figures:

• FIG. 2 shows a sectional view through a portion of a primary pullout 1 consisting of example three juxtaposed hollow sections 2, whose cross-section in this known design (the right two hollow sections 2) is approximately A-shaped, so that the passages 3 taper therebetween in the flow direction 10 and as Nozzle slots act.

In this case, the hollow sections 2 consist of a V-shaped bent sheet which forms a front tip and from this in the flow direction 10 projecting rear side walls, and one in the open back of this sheet, set back from its free ends, tightly inserted, in particular welded-in, back plate 5, which together provide a hollow interior. Secondary air and / or recirculation gas can be supplied via this hollow interior, which is then discharged via outlet openings 4 in the side walls of the hollow sections 2 into the passages 3 and thus the flue gas 14 flowing therethrough.

Because of the supernatant over the back plate 5 out backwards, the gas mixture flowing through the nozzle-like passages 3 behind the back plate 5 on each side of the hollow section 2 a sweeping vortex 19, whereby a good mixing of the flue gases 14 with the supplied secondary air and / or the recirculation gases is achieved from the hollow sections 2 and thus leads to an improved afterburning in the afterburner 21.

• Zum einen ist das freie Ende des Überstandes oder Fortsatzes 6 bereits als schneidenförmige, spitz zulaufende Abrisskante 7 ausgebildet.

Here are in FIG. 2 the two right hollow sections 2 are shown in the known, A-shaped cross-sectional shape, whereas the left-hand hollow section 2 already has an improvement according to the invention:

• First, the free end of the supernatant or extension 6 is already formed as a blade-shaped, tapered spoiler edge 7.

Furthermore, the outer surfaces 2a are spherically shaped from the widest point to the rear to the trailing edge 7, which favor the sweeping vortex, and as a result of which the free ends, that is to say the trailing edges, approach one another.

The back plate is bent so that it has a concave outer surface, ie back, even if they should not run without kinking to the trailing edge 7.

The demolition edges 7 are formed at an acute angle by sharpening the area of these free end edges.

• Wie Figur 3a zeigt, ist das Hohlprofil 2 aus einem Stück eines Rundrohres, also eines Rohres 2 mit kreisrundem Querschnitt, und insbesondere gleichbleibender Wandstärk, hergestellt, welches vorzugsweise lediglich - wie in Figur 4 dargestellt - an seinen Enden einen speziellen Zuschnitt erfährt, um in eine umgebende Struktur eingepasst und stirnseitig aufgelegt werden zu können.

The Figures 3 and 4 show a contrast again improved and even easier to produce in the hollow section 2:

• As FIG. 3a shows, the hollow section 2 is made of one piece of a round tube, ie a tube 2 with a circular cross-section, and in particular constant wall thickness, which preferably only - as in FIG. 4 shown - at its ends undergoes a special blank to fit into a surrounding structure and can be placed on the front side.

It is essential to the invention, however, that in the - apart from these specially designed ends - for the mixing of the flue gases relevant central region in the direction 2 'of the hollow sections 2, in which also in this extension direction 2' spaced a plurality of outlet openings 4 are for secondary air, a Segment strip 29 separated out of the same tube 2 and was re-welded into the resulting recess with the previous inside out, as in the cross-sectional view of FIG. 3a seen.

In this tightly welded state - the frontal openings at the end of the inserted segment strip 29 are sealed by a sealing member 32 against the subsequent complete circular cross-section of the tube 2 - then the back plate 5 has a concave outer surface 5a whose radius of curvature corresponds to the radius of curvature of the pipe inside ,

The resulting by this composition tear-off edges 7 are usually obtuse, but can be formed acute angle by appropriate processing.

As a result, the formation of sweeping vortices 19, as in the FIG. 2 shown further improved by these can be maintained very stable for a long time.

The distance 9 in the transverse direction 11 of the two tear-off edges 7 is about 70% of the width 28, ie the outer diameter of the hollow section 2 in this illustration.

The hollow profile 2 is formed symmetrically to the longitudinal center plane 10 ', which extends centrally and vertically standing on the segment strip 29.

The with respect to this longitudinal center plane 10 'preferably opposite outlet openings 4 are set back from the along the longitudinal center plane widest point of the pipe section 2 in the direction of the back plate 5.

The design of the hollow section 2 according to FIG. 3b is different from the one of FIG. 3a in that the segment strip 29 projects at the point of contact with the tube 2 over its outer circumference by having the same radius of curvature as the tube 2, but a larger segment angle, that is not the segment separated from this tube 2, but from one segment other tube with preferably the same outer and / or inner diameter and preferably the same wall thickness comes.

The ends of this segment strip 29 are viewed in cross-section at an acute angle with an angle at the top of preferably about 50 ° to 70 °, wherein the outer edge has a tendency such that their inclination direction - viewed in the direction 2 '- a tangent to the Outside circumference of the tube 2 represents, as has been found that this promotes the formation of sweeping vortex particularly well.

The ends of the segment strip 29 are preferably not over the widest point of the cross section of the tube 2 before.

The design of the hollow profile according to Figure 3c is different from the one of FIG. 3b in that the segment strip 29 used there in the recess of the tube 2 has a smaller radius of curvature, that is to say from a tube with a larger outer or inner diameter than the tube 2.

Otherwise, here is the segment strip 29 with its ends preferably over the outer circumference of the tube 2 at the contact point before and - in contrast to the ends at FIG. 3b - Preferably over the widest point of the tube 2, so the diameter 28, on both sides before.

As in the design according to Figure 3c the outer edge of the tear-off edge 7 formed as a sharp edge in its extension represents a tangent to the outer circumference of the tube 2, the angle of the acute-angled cutting edge 7 is lower here than in the design according to FIG FIG. 3b only about 40-50 °.

3d figure shows a design in which in the recess of the tube 2 no segment strip of another, in particular round, tube is used and in particular welded, but an angle section.

Otherwise, preferably, the supernatant and the design of the lateral tear edges 7 analogous to those in the FIGS. 3b and 3c be described described.

As FIG. 4 can be seen, the one end of the hollow section 2 is closed at the end, while the left end in the figure is partially open at the front end and an inlet opening 31 forms.

FIG. 5 shows in cross section a two-part design, with only the one part, the front part 2.1, a hollow profile, in this case in one piece, whose rear end in turn forms the back plate 5.

Again, the hollow section 2 is again formed side symmetrical to the longitudinal center plane 10 '.

In the right half of the figure, the front part 2.1 with a cross-sectional contour is like the closed part of the A-shape in FIG FIG. 2 shown in the left half the front part 2.1 is approximately semicircular in cross section, each with a flat, ie straight, back plate. 5

On either side of the longitudinal center 10 'is in each case one of the angled control profile parts 8a, b on the back plate 5, on the outer surface of the bend between the two legs 8a1, 8b1, wherein their inclination relative to the back plate 5 by means of a screw 33 and a these legs 8a1, 8b1 away from the back plate 5 with force acting plate spring 30 is adjustable.

The adjusting screw 33 preferably extends through both of these legs 8a1, 8b1 and is screwed in a threaded hole in the back plate 5, which lies on the longitudinal center plane 10 ', more or less strongly.

The other leg 8a2, 8b2 has a convex outer surface, and at its free end a tapered cross-section tear-off edge 7. The outer surface of the front part 2.1 is preferably flush in the outer surface of this second, freely in the trailing edge 7 expiring, leg 8a2, 8b2 over, preferably so that the widest point of the entire profile in the flow direction 10 is located just behind the back of the back plate 5, ie in the region of the freely extending legs 8a2, 8b2.

In this way, the distance 9 of the two tear edges 7 to each other can be changed depending on the purpose.

FIG. 6a shows a primary passage in the longitudinal direction, the flow direction 10, in which the flow direction 10 of the flue gases 14 extends from bottom to top.

In this primary extraction two consecutive rows 34a, b of hollow profiles 2 are arranged within the surrounding, the flue gases 14 leading housing in the flow direction 10, which are arranged with their ends in receiving bodies rest, over which also at least on one side, the supply of effluent from the hollow sections 2 secondary air takes place, in this case, for example, the one-piece design of the hollow sections 2 according to FIG. 3 is selected.

Within the two rows 34a, b, the hollow profiles 2 are parallel to each other at a distance. The course direction of the hollow profiles of one row 34a extends transversely, in this case at right angles, to the course direction of the hollow profiles 2 of the other row 34b, so that viewed in the flow direction 10, as in FIG FIG. 6b represented, a grid of hollow sections 2 results, which must be traversed by the flue gases 14.

LIST OF REFERENCE NUMBERS

1

primary deduction

2

hollow profile

2.1

front part

2a

outer surface

2a1

front area

2a1

the backstage area

2 '

running direction

3

passage

4

outlet opening

5

backplate

5a

outer contour

6.6 '

extension

7

tear-off edge

8th

control profile

8th'

contact line

8a, b

Control Panel Parts

8a1 / 2

leg

8b1 / 2

leg

9

distance

10

flow direction

10 '

Longitudinal center plane

11

transversely

12

extension

13

recess

14

flue gas

15

recirculation

16

Direct exhaust damper

17

swivel axis

18

regulation flap

19

periodic vortex

20

combustion chamber

21

secondary combustion

22

Combustion chamber door

23

recirculation

24

partition wall

25

hand control

26

fireplace

27

heat exchangers

28

width

29

segment strips

30

Belleville spring

31

inlet port

32

sealing part

33

screw

34a, b

line

Claims (17)

Primary discharge (1) for a solid fuel heater, with - A plurality of tubular hollow profiles (2) which are arranged transversely to their course direction (2 ') spaced from each other, - wherein the at least one clear passage (3) between the hollow profiles (2) form at least one nozzle slot for the flue gases (14) passing in the flow direction (10), - wherein the hollow profiles (2) outlet openings (4), via which flows over the interior of the hollow section (2) supplied secondary air and / or recirculated flue gas into the passages (3), characterized in that - The outer surfaces (2a) of the hollow sections (2), in particular from the flow direction (10) widest point from, to the rear, ie in its rear region (2a 2), the longitudinal center plane (10 ') of the hollow profile (2) approximate . - The outer surfaces (2a) of the hollow profiles (2) in the flow direction (10) in each case a tear-off edge (7) and end - A the two tear-off edges (7) connecting the back plate (5), which forms the rear part of the hollow profile (2) has a concave outer contour (5a). Primary train (1) according to claim 1,
characterized in that
the hollow profiles (2) are formed symmetrically with respect to their longitudinal center plane (10 ') which contains the course direction (2') of the hollow profile (2). Primary train (1) according to one of the preceding claims,
characterized in that - In the direction (2 ') considered the hollow sections (2) in the flow direction (10) of the flue gases (14) from front to back at least in the front region (2a 1) from each other outer surfaces (2a), and / or - The outlet openings (4) in the flow direction (10) before or at the latest at the widest point of the outer contour (2a) of the hollow profile (2) are arranged. Primary train (1) according to one of the preceding claims,
characterized in that - The rear free end of the trailing edge (7) as viewed in cross-section V-shaped edge, in particular as a cutting edge is formed, in particular with a in the direction (2 ') considered edge radius of less than 2 mm, better less than 1 mm, better of less than 0.5 mm, better of less than 0.3 mm, better of less than 0.2 mm, and / or - The tear-off edge (7) is designed as an acute-angled cutting edge whose cutting angle is less than 85 °, better less than 80 °, better less than 75 °, better less than 60 °, better less than 50 °. Primary train (1) according to one of the preceding claims,
characterized in that - The back (5a) of the back plate (5) in the cutting edge designed as a cutting edge (7) without paragraph and without kink with a KnickRadius, which is smaller than 6 mm, better 4 mm, better 2 mm passes, and / / or - The back (5a) of the back plate (5) has a concave curvature whose radius of curvature in particular between 0.5 cm and 5 cm, more preferably between 0.8 cm and 4 cm, better between 1.0 cm and 3 cm, better between 1.3 cm and 2.5 cm is better between 1.4 cm and 2.0 cm. Primary train (1) according to one of the preceding claims,
characterized in that
the back (5a) of the back plate (5) has a concave curvature whose radius of curvature - Deviates in particular by not more than 40%, preferably not more than 30%, preferably not more than 20% of the average radius of curvature of the outer contour of the cross section of the hollow profile, deviates in a tubular profile with annular cross-section of the radius of curvature of the outer periphery of this tube profile and / or - In a tubular profile with annular cross-section of the radius of curvature of the concave curvature of the radius of curvature of the outer contour of the tubular profile by not more than 20%, preferably not more than 10%, preferably not more than 5%. Primary train (1) according to one of the preceding claims,
characterized in that
the hollow profile (2) has an inlet opening (31) for secondary air, in particular in one of its end faces.
(Figure 3a) Primary train (1) according to one of the preceding claims,
characterized in that - viewed in the direction (2 '), the outer surfaces (2a) of the rear portion (2a2) of the hollow section (2) are flat or convex convex, and / or - The distance (9) between the two edges (7) of a hollow section (2) between 30% and 60%, better between 35% and 55%, better between 40% and 50%, the largest width (28) of the outer contour ( 2a) of the hollow profile (2) in the transverse direction (11), in particular the outer diameter (28) of the hollow profile (2) designed as a round tube (2). Primary train (1) according to one of the preceding claims,
characterized in that - The hollow section (2) is a tube (2) with a round cross-section, from which a in the direction of travel (2 ') extending segment strip (29) separated out and - With its previous tube inside out in the resulting recess at the rest of the tube (2) again tightly secured, in particular welded, is. (FIGS. 3b to d) Primary train (1) according to one of the preceding claims,
characterized in that - The hollow section (2) is a tube (2) with a round cross-section, from which a in the direction of travel (2 ') extending segment strip (29) separated out and - Either a segment strip (29 '), in particular another tube with a particular round cross section and other diameter, with its previous tube inside out in the resulting recess on the rest of the tube (2) again tightly secured, in particular welded , is, - Or a strip (29 ') with a considered in the direction (2') bent cross-section with its concave side in the recess of the tube (2) again tightly secured, in particular welded, is. Primary train (1) according to claim 10,
characterized in that - The in the direction of travel (2 ') considered lateral ends of the strip (29') over the recess and in particular over in the flow direction (10) considered widest point of the tube (2) in the transverse direction projecting, but preferably not more than 10%, better still not more than 20%, better still not more than 30% of the width of the tube (2) at the widest point, and / or the outer flank of the tear-off edge (7) designed as an acute-angled cutting edge in the running direction (2 '), with its extension, represents a tangent to the outer circumference of the hollow profile (2) or tangentially in the direction of it by a maximum of 10%, better still a maximum of 20%, better than 30% deviates. Primary train (1) according to one of the preceding claims,
characterized in that
the gap between the in the direction (2 ') front and rear end of the segment strip (29) and the inner circumference of the tube (2) is sealed.
(two-part design) Primary train according to one of the preceding claims,
characterized in that
the hollow profile (2) is formed in two parts with a front part (2.1) which is closed in cross-section except for the outlet openings (4) and one on the rear side of the back plate (5) of the front part (2.1) in the extension direction (2 '), in particular adjacent, detachably mounted control profile (8), which has the rear projecting tear-off edge (7) and in particular in their distance (9) to the front part (2.1) is adjustable. Primary train according to one of the preceding claims,
characterized in that - The control profile (8) is formed in two parts and the two parts (8 a, b) of the control profile (8) are angled and with the outer surfaces of each leg (8 a 1, 8 b 1) against the back of the back plate (5) and by pivoting around this contact line the width (28) the rear end of the control profile (8) and thus the distance (9) between the two separation edges (7) is adjustable, and / or - An adjustable adjusting screw (33) one leg (8a1, 8b1) of each part (8a, b) against the back (5a) of the back plate (5) presses, by a spring, in particular a plate spring (30), in the opposite direction is biased Primary train according to one of the preceding claims,
characterized in that - The front part (2.1) has air passage openings in its back plate (5), and / or - The front part (2.1) in the longitudinal direction (10) spaced extensions (12) to the rear beyond the back plate (5) has standing out, which engage in corresponding recesses (13) of the control plate (8) for their guidance. Heating device for solid fuels, with
a combustion chamber (20) which is connected via a primary exhaust (1) to a secondary combustion chamber (21) in which the flue gases (14) flowing out of the combustion chamber (20) are burned,
characterized in that
the primary pullout (1) is designed according to one of the preceding claims. Heating device according to claim 16,
characterized in that - The primary pullout (1) a plurality in the flow direction (10) one behind the other lying rows (34 a, b) of objected, in particular parallel to each other, extending hollow sections (2), and - Especially the hollow sections (2) of a row (34 a) in the flow direction (10) viewed transversely to the hollow profiles (2) in the flow direction (10) immediately preceding or following row (34 b) extend.

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