DE29719238U1 - Solid fuel boilers - Google Patents

Description

Köb & Schäfer KG , K 2607-Cs/he

Boilers for solid fuels

The present invention relates to a boiler for solid fuels, in particular for wood material, with a filling chamber which is arranged above a combustion grate arranged in a first degassing chamber, wherein a combustion chamber adjoins the degassing chamber and where an automatic feeding device is provided.

Such boilers for solid fuels are generally known and are designed to enable both manual and automatic feeding of the boiler. However, the problem with such known boilers is that one of the two operating modes, i.e. either manual or automatic operation, has always led to unsatisfactory emission values.

The problem (task) underlying the invention is to develop a boiler for solid fuels of the type mentioned at the beginning in such a way that the lowest emission values can be achieved both in manual operation and in automatic operation.

This task is solved in a boiler of the type mentioned above by the automatic loading device opening into the area of a further degassing chamber, which is spatially separated from the first degassing chamber and in which a further combustion grate is arranged. In this case, the further degassing chamber also opens into

the combustion chamber, i.e. two spatially separate degassing chambers are provided for manual and automatic feeding, which lead into a common combustion chamber.

The boiler according to the invention enables the lowest emission values to be achieved for every operating mode, since the material feed through the automatic feeding device is separated from the manual material feed through the additional degassing chamber. The additional degassing chamber thus serves as a kind of separation chamber to ensure trouble-free and low-emission operation.

Advantageous embodiments of the invention are described in the description, the drawings and the subclaims.

According to a first advantageous embodiment, the first and the further degassing chamber can open together into the combustion chamber. This results in optimized flame guidance within the combustion chamber without external interference.

In the area of the first degassing chamber, an automatically controlled first primary air flap can preferably be provided and in the area of the further degassing chamber, an automatically controlled second primary air flap can be provided. If an automatically controlled secondary air flap is also provided, with which air can be fed into the entrance area of the combustion chamber, fully automatic operation of the combustion boiler can be ensured.

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Preferably, the first and the further degassing chamber open at an angle of about 90° to each other. This creates a space-saving arrangement that is also advantageous in terms of flow technology.

According to a further development of the invention, an air space can be provided below the additional combustion grate, i.e. in the area of the automatic loading device, into which a primary air flap preferably opens. Such an air space below the additional combustion grate creates optimal conditions for even and trouble-free combustion in the area of the additional degassing chamber. It is particularly advantageous if the additional combustion grate is designed as a flat grate, since this - in contrast to conventional fire troughs in the area of an automatic loading - enables significantly better emission values to be achieved.

Preferably, the burnout chamber is arranged above the further degassing chamber and separated from it by a fireproof wall. In this embodiment, the channel used as a burnout chamber in conventional construction is used as a separating chamber between the two degassing chambers. The actual burnout chamber is therefore arranged above this separating chamber. The secondary air supply takes place in a mixing chamber into which the degassing chambers open on the one hand and the burnout chamber closes off on the other.

When the combustion gases pass from the further degassing chamber into the combustion chamber, the gases can be diverted by 180° in an advantageous manner. This ensures good mixing of the combustion gases with

Secondary air and thus good combustion are guaranteed in all cases, without the need for vortex formation. It is also advantageous if, when the combustion gases pass from the first degassing chamber into the combustion chamber, the combustion gases are first diverted by 90° and then diverted by a further 90°.

Optimum control of the boiler can be achieved if the control of the two primary air flaps and the secondary air flap is carried out by an automatic control system, which automatically adjusts the air flaps both during manual and automatic feeding. For this purpose, each air flap can be equipped with a stepper motor, with the air flaps being controlled in function of the exhaust gas temperature and the residual oxygen.

The present invention is described below purely by way of example using an advantageous embodiment and with reference to the accompanying drawings.

Show it:

Fig. 1 is a partially sectioned front view of a boiler;

Fig. 2 is a partial sectional view along the line II - II of Fig. 1; and

Fig. 3 is a partial sectional view along the line III - III of Fig. 1.

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Fig. 1 shows the front view of a boiler for solid fuels, the filling chamber 10 of which is closed by a flap 12. The filling chamber 10 is arranged above a first combustion grate 14, which is provided in a first degassing chamber 16 (Figs. 2 and 3). The first degassing chamber 16 opens into a horizontally running combustion chamber 18 via a vertical mixing chamber 20, in which secondary air is mixed in, whereby the combustion gases are diverted by 90° during the transition from the first degassing chamber 16 into the vertical mixing chamber 20 and the combustion gases are diverted again by 90° during the further transition of the combustion gases into the combustion chamber 18, but offset by 90° in plan view. The combustion chamber 18 has an outlet opening upwards (Fig. 1 and 3) through which the combustion gases can flow to a heat exchanger 22 and from there through an exhaust fan 24.

On the side of the boiler, an automatic feeding device is provided in the form of a conveyor screw 26, through which chopped fuel is conveyed to a further combustion grate 28, which is designed as a flat grate. Above the further combustion grate 28, a further degassing chamber 30 is provided, which is, however, separated from the first degassing chamber 16 by a wall made of refractory material 32 (Fig. 3). The further degassing chamber 30 opens upwards into the vertical mixing chamber 20, i.e. the first and the further degassing chambers open together into the combustion chamber 18, which is separated from the further degassing chamber 30 by a horizontal, refractory wall 33. The combustion gases produced in the further degassing chamber 30 initially flow horizontally to the end of the further degassing chamber 30, where they are deflected upwards by 90° and flow into the vertical mixing chamber 20. Above the further degassing chamber

A level sensor 34 is provided at the feed screw 30, which controls the conveyor screw.

In the area of the first degassing chamber 16, a first primary air flap 36 is provided, which opens into an air space below the first degassing grate 14. A second primary air flap 38 for automatic operation is located in the area of the conveyor screw 26 and opens into an air space 40, which is provided below the further combustion grate 28.

Finally, opposite the second primary air flap 38 there is a secondary air flap 42 which opens into a vertically extending secondary air duct 44 which is led to the inlet of the vertical mixing chamber 20.

When the boiler is operated manually, the fuel is filled into the filling chamber 10 through the flap 12 and ignited so that it burns on the first combustion grate 14 and is degassed there within the first degassing chamber 16. The fuel gases then flow after a 90° deflection into the vertical mixing chamber 20, in which secondary air is added, and from there after a 90° deflection into the combustion chamber 18 to burn out completely. The fuel gases emerging vertically upwards from the combustion chamber 18 then flow around the heat exchanger 22 and are conveyed out of the boiler by the exhaust gas fan 24.

In this operating mode, the automatic control of the boiler regulates the first primary air flap 36 depending on the exhaust gas

temperature is set, whereby the second primary air flap 38 is kept closed. The secondary air flap 42 is regulated depending on the residual oxygen content.

In automatic operation, i.e. when the conveyor screw 26 is operating, the fuel is conveyed by this to the further combustion grate 28 and ignited there. The height of the fuel is regulated by the level sensor 34. In this mode of operation, the automatic control of the boiler works in such a way that the first primary air flap 36 is kept closed, whereas the second primary air flap 38 is regulated depending on the exhaust gas temperature. Here too, the secondary air flap 42 is regulated depending on the residual oxygen content.

The boiler according to the invention enables the lowest emission values to be achieved, as it is optimized for both manual and automatic feeding. The clever spatial separation of the two degassing chambers ensures trouble-free operation in both operating modes, with the flow of the combustion gases always following the specified channel through the mixing chamber 20, in which secondary air is mixed, into the combustion chamber 18. Since no tangential inflow of the combustion gases or the secondary air is provided, the mixing of the combustion gases can take place without turbulence.

K2607-Cs/he List of reference symbols

10 Filling chamber

12 flap

14 first combustion grate

16 first degassing room

18 Burnout chamber

20 vertical mixing chamber

22 heat exchangers

24 exhaust fan

26 Conveyor screw

28 additional combustion grate

30 additional degassing room

32 Wall

33 Wall

34 Level probe

36 first primary air flap

38 second primary air flap

40 Airspace

42 Secondary air flap

44 Secondary air duct

Claims (14)

• · · to K 2607-Cs/he claims 1. Boiler for solid fuels, in particular for wood material, with a filling chamber (10) which is arranged above a combustion grate (14) arranged in a first degassing chamber (16); a burnout chamber (18) adjoining the first degassing chamber (16); and
an automatic feeding device (26); characterized in that the automatic feeding device (26) opens into the area of a further degassing chamber (30) which is spatially separated from the first degassing chamber (16) and in which a further combustion grate (28) is arranged; and that the further degassing chamber (30) also opens into the combustion chamber (18). 2. Boiler according to at least one of the preceding claims, characterized in that the first and the further degassing chamber (16, 30) open together into a mixing chamber (20), to which the burnout chamber (18) is connected. 3. Boiler according to claim 1, characterized in that a preferably automatically controlled first primary air flap (36) is provided in the region of the first degassing chamber (16). 4. Boiler according to at least one of the preceding claims, characterized in that a preferably automatically controlled second primary air flap (38) is provided in the region of the further degassing chamber (30). 5. Boiler according to at least one of the preceding claims, characterized in that a preferably automatically controlled secondary air flap (42) is provided, to which an air duct (44) is connected, which opens into the mixing chamber (20). 6. Boiler according to at least one of the preceding claims, characterized in that the first and the further degassing chamber (16, 30) open at an angle of approximately 90° to one another. 3 - 7. Boiler according to at least one of the preceding claims, characterized in that an air space (40) is provided beneath the further combustion grate (28), into which a primary air flap (38) preferably opens. 8. Boiler according to at least one of the preceding claims, characterized in that the further combustion grate (28) is designed as a flat grate. 9. Boiler according to at least one of the preceding claims, characterized in that the combustion chamber (18) is arranged above the further degassing chamber (30) and is preferably separated from it by a fireproof wall (33). 10. Boiler according to at least one of the preceding claims, characterized in that during the transition of the combustion gases from the further degassing chamber (30) into the mixing chamber (20) a deflection of 90° upwards occurs. 11. Boiler according to at least one of the preceding claims, characterized in that when the combustion gases pass from the first degassing chamber (16) into the mixing chamber (20), a deflection of 90° upwards takes place. 4 - 12. Boiler according to at least one of the preceding claims, characterized in that an automatic control is provided which regulates the two primary air flaps (36, 38) and the secondary air flap (42). 13. Boiler according to claim 12, characterized in that the control has a first operating mode for manual loading and a second operating mode for automatic loading, by means of which the second primary air flap (38) is closed in the first operating mode and the first primary air flap (36) is closed in the second operating mode. 14. Boiler according to at least one of the preceding claims, characterized in that immediately after the mixing chamber (20) the combustion gases are diverted by 90° to flow into the combustion chamber (18).