EP2592339B1 - Solid fuel burning device - Google Patents

Description

I. Field of application

The invention relates to a solid fuel combustion device and in particular the formation of the combustion grate.

II. Technical background

• Zwar sind grundsätzlich mindestens zwei verschiedene Arten des Abbrandes zu unterscheiden, nämlich einmal aus dem Primär-Brennraum heraus nach unten durch den Brennrost oder nicht nach unten, sondern nach oben oder zur Seite in einen Nachbrennraum. Dennoch ist bei beiden Verfahren der Brennrost nie ganz geschlossen, sondern zumindest bereichsweise luftdurchlässig, denn auch beim Abbrand nicht nach unten wird von unten stattdessen Primärluft für die Verbrennung durch den Brennrost zugeführt.

In the case of solid fuel burning devices, the fuel is located during the burnup on the bottom of the primary combustion chamber, which is formed at least in some areas as a combustion grid:

• Although fundamentally at least two different types of burnup are to be distinguished, namely once from the primary combustion chamber out down through the combustion grate or not down, but up or to the side in a Nachbrennraum. Nevertheless, in both methods, the combustion grate is never fully closed, but at least partially permeable to air, because even when burning down is instead fed from below instead primary air for combustion through the combustion grate.

The grate is thermally highly loaded because of its proximity to the kiln and subjected to strong thermal interactions. In addition, he must meet other requirements, such as a long life and easy cleaning.

In this context, it has hitherto been known to form the combustion grate from two plates arranged one above the other, each having mutually aligned passages, but by relative movement to each other, these passages can be completely or partially closed.

The passages serve in the fully open state on the one hand the improved fall through of ash, on the other hand, the supply of optimally much primary air.

The disadvantage is that when a desired high primary air supply automatically not only ash, but also embers pass through the then large aligned openings, which is not desirable.

In addition, the top plate of the combustion grate has no flat, easy-to-clean surface, but on the contrary usually has upwardly directed ridge-shaped bulges that complicate the cleaning.

Above all, however, the degree of primary air supply can be set by the user between zero or nearly zero and full opening of the passages, the latter being extremely detrimental to complete combustion and high efficiency of the heater.

This is the purpose of the DE 8529534 U1 switching between two fuels, ie burning wood without primary air and burning coal with a lot of primary air.

The DE 610704 on the other hand, in the operating condition in which the apertures of the two plates are out of alignment with each other and no primary air is supplied through the apertures of the lower plate, a partial cooling of the upper plate by the lower, cooler, non-penetrating primary air prevails.

Furthermore, from the JP 58-72804 a firebox floor known, which consists of two layers of superimposed and relatively movable strips, in each of which ash-discharge openings are formed, which can be brought to each other by relative displacement more or less in coverage.

Likewise is from the EP 0 945 676 A2 a furnace floor known, which consists of two superimposed, mutually rotatable plates with primary air openings, which can be brought by relative rotation to each other more or less in coverage.

III. Presentation of the invention a) Technical task

It is therefore the object of the invention to provide a solid fuel combustion device with a combustion grate available, on the one hand allows easy cleaning and ash removal during cleaning, on the other hand automatically assumes the correct setting for correct primary air supply for combustion operation.

b) Solution of the task

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

The combustion grate according to the invention is easy to clean and spend the ashes in the underlying ash container by the large area, in particular identically shaped, ash openings of the two combustion grate plates are aligned with each other and this is a drop of ash down into the ash tray very easily is possible, for. B. with a hand brush or the like.

This is additionally facilitated by the top of the top plate of the upper grate plate is flat, so that a sweeping or return to the ash openings is very easily feasible.

In the operating position, however, the two grate plates are arranged to each other so that the ash openings at most partially or not at all aligned. The primary air is then supplied via the remaining passage of either the aligned ash openings or through special primary air openings in at least one of the two plates which are aligned with analog primary air openings in the other plate or with a part of the ash openings in Cover the other plate in this operating position.

The relative movement of the two grate plates to each other can be a linear sliding movement, z. B. in the direction of the firebox door or transverse to this direction, or be a rotational movement about a vertical axis, at least preferably by a movement in the plane of the plate.

If the ash openings are elongated, their direction of extension may be longitudinal or transverse to the direction of movement.

Regardless, the movable combustion grate plate should have a mechanical connection to the inside of the firebox door, which is effective at least in the closed state of the firebox door and automatically moves the movable grate plate with closed firebox door in the operating position and holds there, in particular by positive engagement.

This ensures that during use of the heater is not accidentally the ash openings are continuously open (cleaning position) and over this way a much too large amount of primary air into the combustion chamber device, but only by dimensioning the primary air openings or by corresponding small overlaps of the ash openings intended combustion air quantity.

A very simple mechanical coupling consists in a directed from the movable plate to the firebox extension that is so long that when you close the firebox door inside the firebox pushes the extension in front of him and thereby pushes or rotates the movable plate in the operating position.

Preferably, the lower of the two grate plates, the movable plate and the upper immovable inserted in the furnace chamber plate.

To the heater still with one and the same movable grate plate on different z. For example, to adjust fuel materials that require more or less primary air, different positions may be provided in the firebox floor for the fixed firewall plate which, together with the movable plate in the operating position, leave different sized free passages for the primary air vent.

For example, in the case of a rectangular solid combustion grate plate, this may be a different longitudinal position in the direction away from the firebox door, or else a rotation of the solid grate plate about the vertical axis 180 °, in which case the ash openings may not be arranged exactly symmetrical to the center of the plate, but so eccentrically that due to the other rotational position results in a different degree of coverage with the ash openings and / or the primary air opening in the other plate in the operating position.

The primary air supply can also take place, for example, in that the primary air does not flow through the two plates through aligned openings from bottom to top, but must flow horizontally between the plates at a height distance from one opening in the lower plate to the next opening in the upper plate. Then the primary air quantity is determined by which passage cross sections are present on this horizontal flow path between the plates. Edge-side distances between the grate plate and the combustion chamber floor are suitable for this purpose.

For this purpose, in the bottom of the upper plate and / or the upper side of the lower plate z. B. special channels may be present.

For example, it has been found that it makes sense to design the upper combustion grate plate with a planar upper side on the underside in such a structured manner that only at the lower edge and / or circumferentially around the ash openings and possibly also as connecting webs there is a large plate thickness, while the remaining areas of the plate have a lower thickness.

At these areas of large plate thickness is then only a very small, ideally no distance between upper and lower plate in the operating position, so that the ascending ascending amount of primary air is determined, either by exact adjustment of the distance of the two plates to each other, which is because of Heat distortion is often difficult, or just by targeted dimensioning of passageways in the bottom of this otherwise the crossflow obstructing webs or edges of the ash openings.

In a preferred embodiment, one or both of the grate plates can be designed so that in the operating position with increasing heating, especially the upper grate plate whose thermal expansion causes, thereby narrowing the passageways for the primary air automatically and their supply is reduced. Since the thermal expansion along the largest direction of extension of the plate is the strongest, the effect in this direction should be primarily exploited.

In addition, a fine adjustment of the movable grate plate can be provided in the operating position, which allows further optimization of the combustion device to the current operating parameters, be it particulate matter CO or CO ₂ or other parameters, such as the fuel used and its properties.

By this fine adjustment, the amount of primary air supplied to the combustion should be precisely adjustable.

In the apparatus according to the invention, this is done either by changing the vertical distance between the lower and the upper grate plate through which also primary air flows upward into the combustion chamber and / or by changing the coverage of existing in the two combustion grate openings, be it the ash openings and / or the primary air openings.

This fine adjustment should be possible from outside the combustion device, especially because outside the combustion device, a motor can be placed on such a setting device, which is controlled by a controller, for example, receives input signals from a lambda probe or other sensor of the combustion device, during the operation, So in the operating position of the movable grate plate, can be controlled and changed.

One possibility is the relatively slight displacement, so adjusting, the position of the movable grate plate in the operating position.

On the one hand, the overlap of the primary air openings present in the combustion grate plates can be selectively changed.

On the other hand, by means of the wedge surfaces present in the direction of movement of the movable plate, in particular the movable grate plate, the height distances can be changed by which primary air can flow from the ashtray upwards into the combustion chamber. These can z. B. be present on the top of the support plate corresponding wedges on the longitudinally moving the grate plate the grate plate is additionally pushed and thereby the height distance is changed to the opposite solid grate plate.

Another possibility is to perform the wedges along the support plate and thus relative to the movable grate plate movable and move their position, whereby the grate plate remains in the longitudinal direction in position, but changes their altitude.

Also adjustability of the length of the extension, with which the firebox door when closing the movable firing plate pushes in front of him, is possible, for example, by means of threaded rod and spindle nut to adjust the operating position exactly.

c) embodiments

Fig. 1a - d:

die bewegliche Brennrostplatte,

Fig. 2a, b:

beide Brennrostplatten auf der Tragplatte im zusammengesetzten Zustand,

Fig. 2c:

die obere, feste Brennrostplatte in der Ansicht von unten,

Fig. 3a:

die Tragplatte alleine,

Fig. 3b - d:

die bewegliche, untere Brennrostplatte einzeln,

Fig. 4a - c:

eine weitere Bauform des Brennrostes.

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

Fig. 1 a - d:

the mobile fire grate plate,

2 a, b:

both grate plates on the support plate in the assembled state,

Figure 2 c.:

the upper, solid grate plate in the view from below,

Fig. 3 a:

the support plate alone,

3 b - d:

the movable lower combustion grate plate individually,

4 a - c:

Another design of the burner grate.

• Wie am Besten die Figuren 2a, b zeigen, besteht der Brennrost 3 - von oben nach unten - aus einer Abfolge von drei Platten:
  • die obere Brennrostplatte 3a,
  • die untere Brennrostplatte 3b und
  • die diese beiden Brennrostplatten 3a,b tragende Tragplatte 9.

In the FIGS. 1 to 3 a first design of the burner grate 3 is shown:

• How best the FIGS. 2a, b show the combustion grate 3 - from top to bottom - from a sequence of three plates:
  • the upper firing plate 3 a,
  • the lower grate plate 3 b and
  • the two these grate plates 3 a, b supporting support plate. 9

• Auf der Oberseite der oberen Brennrostplatte 3a des Brennrostes 3, der somit der Feuerraumboden 2a des über dem Brennrost 3 befindlichen primären Brennraumes 2 ist, liegt der Brennstoff auf und brennt ab. Die Ascherückstände sollen dabei in das unter den Brennrost 3 vorhandene Aschefach 14 und den darin befindlichen Aschebehälter 12 hineinfallen, wie später erläutert wird.

The FIGS. 2a, b Also, it is best shown the arrangement within the solid fuel burning apparatus 1 :

• On the top of the upper grate plate 3 a of the combustion grate 3 , which is thus the combustion chamber floor 2 a of the located above the combustion grate 3 primary combustion chamber 2 , the fuel is on and burns off. The ash residue should fall into the existing under the grate 3 ash tray 14 and the ash container 12 therein, as will be explained later.

In Fig. 2b left is the front of the combustor 1, and there is a furnace door 4 is arranged, which can be opened and closed, for example, to insert fuel into the primary combustion chamber 2 or spend the ash through the grate 3 down into the ash tray 14 .

The fuel gases flow from the primary combustion chamber 2 horizontally to the rear through the fuel gas vent 13 in either a post-combustion chamber 15 or directly into the chimney.

How best that FIG. 2a shows, the support plate 9 of the burner grate 3 as the bottom plate on corresponding edge-side supports 2 b of the side walls of the burner device 1 on.

On the upper side of the support plate 9 lie - each in defined positions, preferably positively fixed - on the one hand, the lower of the two grate plates 3b , which is in this case the displaceable in the longitudinal direction 10 grate plate, and extending over this movable grate plate 3 b away the upper, solid grate plate 3a, which rests with its edge regions - ie outside the lower, smaller, movable grate plate 3 b - also on the support plate 9 , but normally no contact with the top of the lower movable grate plate 3 b, but to this a small, defined height distance 16 complies.

In a region above the ash tray 14 , the support plate 9 has - as best in Fig. 3 to recognize - a large-scale breakthrough 19.

In this breakthrough 19 is - how best the FIGS. 1a to 1d show - the lower, movable grate plate 3b inserted and closes this breakthrough largely. By moving this movable grate plate 3 b in the longitudinal direction 10, in this case on the furnace door 4 to or from this away, the position of the ash openings 5, which are arranged as openings from top to bottom relatively large area in the movable grate plate 3 b, in the longitudinal direction 10th be adjusted. In the present case, these ash openings 5 are slot-shaped transversely to the direction of movement 10, the longitudinal direction, formed and arranged, but they could also have a different shape and / or be arranged along the direction of displacement of this movable grate plate 3 b.

How best that FIGS. 1 a in the view from diagonally above and Fig. 1 b in the view obliquely from below, the movable grate plate 3 b is a bent sheet metal part - as best in the Figures 3b to 3d seen - which laterally projecting support lugs 18 , with which it rests on the edges of the support plate 9 around the opening 19 around. In order to ensure a good guide in the longitudinal direction 10 , the longitudinal edge portions between the support lugs 18 are bent by 90 ° down and represent upright guide rails 17 , with which the plate 3 b is positively guided along the edges of the opening 19 , the in turn also have downwardly folded edge regions in the support plate 9 .

Above the movable grate plate 3 b is the fixedly positioned grate plate 3 a - which consists of a highly refractory material such as cast steel - and extends over the entire front portion which extends in all four horizontal directions beyond the surface of the underlying movable grate plate 3 . Also in the upper fixed movable grate plate 3 a two analog ash openings 5 ' are arranged.

If now - as in Fig. 1c shown - the movable grate plate 3 b completely forward to the firebox door 4, ie in Fig. 1c is shifted to the left, are the ash openings 5 of the lower movable grate plate 3 b and the ash openings 5 'of the upper, fixed grate plate 3 a aligned over one another (cleaning position), and in this position, by means of a hand broom or also reciprocating the movable grate plate 3 b, the ashes through the grate and these ash openings 5, 5 ' fall down into the ash tray 14 .

For this purpose, the top of the upper, solid grate plate 3 a, yes on the firing rests, preferably flat, so that there is also easy sweeping and pushing the ash to the ash openings 5 out.

Since the upper grate plate 3 a is directly in contact with the fire of the burn, this reaches the highest temperature of the three plates, and is inter alia for this reason often of casting with a thick wall thickness, while the lower movable grate plate 3 b and / or the support plate 9 is preferably made of sheet steel as a bent part.

In the in Fig. 1c shown cleaning position is a arranged on the underside of the movable grate plate 3 b and in the longitudinal direction 10 forward on this grate plate 3 b projecting extension 6 to over the plane of the closed combustion chamber door 4, as in Fig. 1c is shown, before, so that the movable grate plate 3 b can take this cleaning position only when the open firebox door 4 .

If the firebox door 4, on the other hand, closed, it pushes automatically by pressure on the free end of this extension 6, the movable grate plate 3 b in the in Fig. 1d shown operating position to the rear, as shown, the lower ash openings 5 with the upper ash openings 5 ' no longer or at least not completely aligned. Whether and to what extent they are aligned in this operating position, can also be changed by the upper fixed grate plate 3 a, for example, rotated 180 ° about its vertical axis is inserted, if then results in a different overlap of the ash openings 5, 5 ' in the operating position.

• Denn bei vollständig zueinander fluchtenden Ascheöffnungen 5, 5', wie in der Reinigungsstellung 1c, würde sehr viel Verbrennungsluft von unten, durch das Aschefach 14 und die Ascheöffnungen 5 nach oben in den Brennraum 2 aufsteigen, und dort zu einem Sauerstoffüberschuss und einer sehr schnellen Verbrennung führen, was im Sinne der Effizienz in der Regel nicht gewünscht ist.

The whole or at least partially closing the ash openings 5, 5 ' in the operating position of Fig. 1d is of great importance for the amount of the primary combustion chamber 2 combustion air supplied, which significantly influences the burnup:

• For with completely aligned ash openings 5, 5 ', as in the cleaning position 1 c, a lot of combustion air would rise from below, through the ash tray 14 and the ash openings 5 up into the combustion chamber 2 , and there to an excess of oxygen and a very fast Incineration, which is usually not desirable in terms of efficiency.

• Zum Einen befinden sich in der beweglichen Brennrostplatte 3b neben den großflächigen Ascheöffnungen 5 wesentlich kleinflächigere Primärluft-Öffnungen 7, und zwar vorzugsweise in einer solchen Position, dass sich diese bei Betriebsstellung gemäß Fig. 1d unterhalb der Ascheöffnungen 5' der oberen Brennrostplatte 3a befinden und die Primärluftöffnungen 7 mit ihrem Querschnitt also den Strömungsquerschnitt für von unten einströmende Verbrennungsluft bestimmen.

Instead, in the operating position of Fig. 1d set the amount of combustion air to be supplied differently:

• On the one hand are in the movable grate plate 3 b next to the large ash openings 5 much smaller-sized primary air openings 7, and preferably in such a position that they are in accordance with operating position Fig. 1 d be located below the ash openings 5 'of the upper grate plate 3 a and the primary air openings 7 so determine the flow cross-section for incoming from below combustion air with its cross section.

• Zwischen der Oberseite der beweglichen, nach unten auf der Tragplatte 9 aufliegenden, Brennrostplatte 3b und der oberen festen Brennrostplatte 3a sollte auch unter Temperaturbeeinflussung ein Abstand 16 vorhanden sein, der somit eine Primärluft-Einströmung in zusätzlichem, geringem Maß vom Ascheraum 14 aus durch die unteren Ascheöffnungen 5, dann in horizontaler Längs- oder Querrichtung durch den Spalt des Abstandes 16 und weiter nach oben durch die dazu versetzten oberen Ascheöffnungen 5' in den Brennraum 2 ermöglicht.

However, it can also combustion air in additional, other ways in the combustion chamber 2 at the operating position of the movable combustion grate plate 3 b flow, which is best based Fig. 2b it is apparent:

• Between the top of the movable, resting on the bottom of the support plate 9 , the grate plate 3 b and the upper fixed firing plate 3 a should be present under temperature influence, a distance 16 , which thus a primary air inflow in addition to a small amount of Ashtray 14 from the lower ash openings 5, then in the horizontal longitudinal or transverse direction through the gap of the distance 16 and further up through the staggered upper ash openings 5 ' in the combustion chamber 2 allows.

The distance 16 is such that it is retained even if thermal distortion of the partially red hot in operation upper combustion grate plate 3 a.

Fig. 2c shows the upper grate plate 3 a in the view from below. In this case, the upstanding webs 21, which also form a ribbing away from the peripheral edge of the ash openings, and the ash openings 5 ' surrounding edges 20 which rise slightly higher than the webs 21, and thus define the distance 16 in the assembled state ,

By this ribbing, which may also include a compound of the raised edge 20 to the raised webs 21 , receives the upper grate plate 3 a high stability and torsional rigidity, even at high temperature.

In order even in the event that due to thermal distortion in operation, the distance 16 should tend to zero, even on this cross-flow path to get a defined amount of combustion air into the combustion chamber 2 , can - as in Fig. 2 c at the upper ash opening 5 ' exemplified - incorporated in the surface of the raised edge 20 one or more grooves 22 which pass through the edge 21 and thus always allow a cross-flow of combustion air into this ash opening 5' inside.

The FIGS. 4a-4c show a further design of the combustion grate 3, in which only the lower, movable grate plate 3 b and the support plate 9 carrying them are shown.

The design of the Figures 4a-4c is different from the one of Figures 1-3 in that on the upper side of the support plate 9, wedges 26 project upwards, which have a wedge surface rising in the longitudinal direction 10, the direction of displacement of the movable combustion grate plate 3 b. Each of the support lugs 18, with the movable grate plate 3 b rests on the top of the support plate 9 , so that by synchronous movement of the wedges 26 in or against the longitudinal direction 10, they slide under the support lugs 18 and raise the movable grate plate 3 b slightly the height distance 16, as he in FIG. 2b is drawn, and thus the passage possibility for primary air is changed.

The displacement of the wedges 26 is thereby possible from outside the firing device by each wedge 26 is fixed to a spindle nut 24 , which is located laterally next to the opening 19 below the support plate 9 and rotationally fixed thereto, wherein the wedge 26 by a corresponding breakthrough in the support plate 9 or even within the opening 19 projects upwards.

The two longitudinally one behind the other threaded nuts 24 each side are penetrated by a common threaded rod 23 , which essentially only in the threaded nuts 24 have a thread, otherwise round rods and in bearing blocks 25 which are also attached to the support plate 9 , rotating are stored.

These threaded rods 23 extend through the housing of the ash compartment to the outside, preferably not by the fire door therethrough, but by an underlying or overlying fixed aperture portion, and can from the outside - to be rotated and thereby the wedges are adjustable in longitudinal direction - manual or motorized.

A controlled, motor drive can be adjusted, for example, depending on a lambda probe or another sensor in the direction of more or less primary air.

LIST OF REFERENCE NUMBERS

1

Solid fuel combustor

2

Primary combustion chamber

2 a

Firebox floor

2 b

edge bearing

3

burning rust

3 a

solid grate plate

3 b

movable grate plate

4

Fire door

5, 5 '

Ash openings

6

extension

7

Primary air opening

8th

upheaval

9

support plate

10

longitudinal direction

11

vertical axis

12

ash container

13

Combustion gas extraction

14

ash tray

15

secondary combustion

16

height distance

17

guide rail

18

supporting nosepiece

19

breakthrough

20

edge

21

web

22

gutter

23

threaded rod

24

screw

25

linear guide

26

wedge

Claims (12)

1. A solid fuel combustion device (1) comprising:

   - a primary combustion chamber (2),

   - a combustion grate (3), configured as a portion of a base (2a) of the primary combustion chamber (2), an ash compartment under the primary combustion chamber, and

   - a front side combustion chamber door (4) of the primary combustion chamber (2),

   - wherein the combustion grate (3) is made from two combustion grate plates (3a, b) arranged on top of one another wherein the combustion grate plates include at least one, advantageously plural ash openings (5, 5') and are arranged in a base of the primary combustion chamber (2) so that the combustion grate plates are movable relative to each other, so that

   - the combustion grate plates are positionable in a cleaning position with the ash openings (5, 5') with the ash openings (5, 5') aligned on top of one another, or

   - the combustion grate plates are arrangeable in an operating position where the combustion grate plates are moved relative to each other so that the ash openings (5, 5') of the two combustion grate plates (3a, b) are only partially aligned with each other or not aligned with each other at all,

   characterized in that
   a combustion grate plate (3b) that is movable relative to the combustion chamber base (2a) has a mechanical connection with the combustion chamber door (4) which mechanical connection is operative at least in a closed condition of the combustion chamber door (4) and which moves the movable combustion grate plate (3b) into the operating position automatically and retains the movable combustion grate plate in the operating position when the combustion chamber door (4) is closed.
2. The solid fuel combustion device according to claim 1,
   characterized in that
   one of the two combustion grate plates (3a, b) is fixated with respect to the combustion chamber base (2a) and another of the two combustion grate plates (3a, b) is movably arranged with respect to the combustion chamber base (2a) and the movable plate (3b) is moveably supported in particular in the longitudinal direction (10), thus towards the combustion chamber door (4) or away from the combustion chamber door (4).
3. The solid fuel combustion device (1) according to claim 2,
   characterized in that
   a protrusion (6) protrudes from the movable combustion grate plate (3b) in a direction towards the combustion chamber door (4) so that the combustion chamber door (4) pushes the movable combustion grate plate (3b) into the operating position automatically through the protrusion (6) when the combustion chamber door (4) is closed.
4. The solid fuel combustion device (1) according to one of the preceding claims,
   characterized in that
   the combustion grate plates (3a, b) are rotatable relative to each other about a vertical axis (11) and a protrusion (6) protrudes eccentrical towards the combustion chamber door (4) at the combustion grate plate (3b) that is rotatable relative to the combustion chamber base (2a), so that the combustion chamber door (4) rotates the rotatable combustion grate plate (3b) into the operating position through the protrusion (6) in a closed condition of the combustion chamber door (4).
5. The solid fuel combustion device (1) according to one of the preceding claims,
   characterized in that

   - at least one primary air opening (7) is arranged in at least one of the two combustion grate plates (3a, b) in addition to the ash openings (5, 5') so that the at least one primary air opening (7) in a first plate (e.g. 3a) is aligned with an analog primary air opening (7) or with one of the ash openings (5, 5') in the other plate (e.g. 3b) and in particular

   - the ash openings (5, 5') have much larger surface areas and/or are much more numerous than the primary air openings (7).
6. The solid fuel combustion device (1) according to one of the preceding claims,
   characterized in that

   - the lower combustion grate plate is the movable combustion grate plate (3b) and/or the upper combustion grate plate is the fixated combustion grate plate (3a) and in particular has a flat top side and/or

   - the upper combustion grate plate (3a) has bulges (8) at a bottom side at least along an edge of the ash openings (5, 5'), in particular also bar shaped bulges (8) between the ash openings (5, 5') and in particular the bulges (8) about the ash openings (5, 5') are the tallest bulges (8) which protrude in a downward direction beyond a remainder of a bottom side.
7. The solid fuel combustion device (1) according to one of the preceding claims,
   characterized in that
   both combustion grate plates (3a, b) rests on a support plate (9) which rests on edge supports (2b) of the combustion chamber base (2a) and in particular a defined elevation distance (16) is provided between the two combustion grate plates (3a, b).
8. The solid fuel combustion device (1) according to one of the preceding claims,
   characterized in that

   - an ash container (12) of the heating device is arranged below the ash openings (5, 5') in the present position, and/or

   - a combustion gas exhaust (13) is arranged in a top side or rear wall of the primary combustion chamber (2).
9. The solid fuel combustion device (1) according to one of the preceding claims,
   characterized in that

   - the combustion grate plate (3a) that is fixated with respect to the combustion chamber base (2a) is insertable in plural positions, in particular rotated about a vertical axis (11), wherein the positions differ with respect to the a clear passage for the primary air in the operating position relative to the movable combustion grate plate (3b) that is in the operating position and/or

   - at least one of the two combustion grate plates (3a, b), in particular the upper combustion grate plate (3a) is configured with respect to pass through options for the primary air so that pass through cross sections for the primary air decrease with increasing heating and thermal expansion of the at least one combustion grate plate (3a, b).
10. The solid fuel combustion device (1) according to claim 6 or claim 7,
    characterized in that

    - pass through channels are provided in the bulges (8) at the bottom side of the upper combustion grate plate (3a) for a transversal flow of primary air between the lower and the upper combustion grate plate (3a, b) and/or

    - wedges (26) are arranged at the top side of the carrier plate (9) in a portion where the moveable combustion grate plate (3b) contacts the carrier plate (9) with its contact lugs (18) so that a movement of the movable combustion grate plate (3b) in particular in the longitudinal direction (10) moves the movable combustion grate plate up or down on a slope of the wedges (26).
11. The solid fuel combustion device (1) according to one of the preceding claims,
    characterized in that

    - the movable combustion grate plate (3b) is movable from an outside by a drive device extending out of the combustion device (1), in particular by at least one threaded rod, and/or

    - the mechanical connection between the combustion chamber door and the movable combustion grate plate (3b), in particular the protrusion (6) is adjustable, in particular the protrusion (6) is length adjustable.
12. The solid fuel combustion device according to claim 7,
    characterized in that
    wedges (26) protrude in an upward direction from the top side of the carrier plate (9) in a portion of the contact lugs (18) and the wedges (26) are movable in a linear manner from an outside in particular by a threaded rod (23) in a movement direction of the combustion grate plate (3b).

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