EP3491294A2

EP3491294A2 - Solid fuel burner

Info

Publication number: EP3491294A2
Application number: EP17772294.9A
Authority: EP
Inventors: Dimitar Dimitrov
Original assignee: Distand GmbH
Current assignee: Distand GmbH
Priority date: 2016-06-02
Filing date: 2017-05-30
Publication date: 2019-06-05
Also published as: WO2017205884A2; AT518707A1; US20190162403A1; WO2017205884A3; RU2018142331A3; AT518707B1; RU2731686C2; RU2018142331A

Abstract

Slag (28) is formed during the combustion of solid fuels with a lower ash fusion temperature and covers parts of the solid fuel, prevents complete combustion and blocks the air supply, thereby leading to an interruption of the combustion process. According to the invention, the embers and the fusing ashes are mixed by means of a cleaning comb (22) and are discharged from the burner. The burner consists of rotating grate bars (25) which are arranged parallel to one another within the inner walls (1). The cleaning comb (22) moves between the grate bars (25); upwards between the grate bars (25); in direction of the burner opening; downwards under the grate bars; and finally in the direction of the burner flange (7). When the slag (28) adheres to the rotating grate bars (25), it is scraped off by the cleaning comb (22). The fuel supplied to a funnel (8) slides downwards by the force of gravity, the funnel lid (9) opens, and the fuel is pushed onto the grate bars (25) by the plunger (11). The plunger (11) has at least one opening (15) for secondary air (5) which also provides cooling. A blower (13) blows the ashes fallen through the grate bars (25) through a cut-out section in the burner floor (30) opened by the floor trap (20).

Description

Solid fuel burner

Technical area

The present invention relates to a novel burner intended for the combustion of solid fuels, in particular, but not exclusively pellets and wood chips, which may also have lower than prescribed according to the class A2 according to the EN 14961-2 melting temperature of the ash. These are e.g. Agro-waste pellets, peat, and others having a melting temperature of the ashes below 1100 ° C.

State of the art

From the prior art, a pellet burner is known, which is intended for the combustion of solid fuels, in particular pellets. (WO 02/079693 A1). The burner has at intervals mutually parallel hollow grate bars. Primary air is passing through the hollow grate bars in the under these

located ash chamber and further between the hollow grate bars and passed over the arranged in front of the hollow grate bars open front plate in the firebox.

The combustion of low melting temperature fuels of the ashes in this and similar burners results in a fusion of the ash and formation of slag which causes the supply of primary air through the grate bars and / or

drilled plates (e.g., IWABO VILLA-S1; ECOVARM-E). The cleaning of such burners can only be done with compressed air from a compressor. This leads to two problems: cyclic work of the burner, and projectile noise at each burner cleaning. Cases are known where the drilled plates overheat from the high temperature and deform.

An attempt to solve this problem with low melting temperature fuels of the ash exists in the burners with sliding grate (e.g., IWABO VILLA-S2, ECOVARM-E +), and in burners with a tilting grate (e.g., HERZ Pelletstar).

Disadvantage of these burners is the cyclic work of the burner - after the

Burning a certain amount of pellets, the burner is full of ash and / or slag. Then the burner should go on burnout, stops the

Burning process, and is cleaned. The worse the pellets, the shorter the

Burning phase. For some pellets - e.g. Peat pellets - is the time for lighting, burnout, and cleaning greater than the time the burner is burning

Burning fuel. This leads to power reduction (eg if the burner operates in the combustion phase for only 20 minutes in one hour, and the remaining 40 minutes in the ignition phase, the burn-out phase and the cleaning phase). Burners are known for solid fuels, in particular for pellets and wood chips, which are provided with step-pushing grates (eg heart Firematik, Strebel Taurus). The movement of every other grate shifts fuel and / or embers. The top grate should clean the bottom grate when moving. With slag-forming fuels, slag, ash and unburned fuel often stick together in a mass that covers the burner, thus preventing the supply of air. Cases are known where slag adheres to the lower grid and the upper grid slips over the slag. Thus, a large amount of air flows between both grates, and they burn through.

Besides, at fusion of ash fuel from the

encased in melted ash. The slag prevents the supply of air to the fuel on the grate, and thus this fuel is not burned. So we have a higher percentage of unburned fuel in the ash tray.

Another attempt to solve the problem of slag formation is the burner of the Kesseis Verner A251. This one has a movable grate that runs through the

Averages the grate plate linearly moved forward and upward, and then returns. This rust is intended to dissolve the slag from the burner plate. In fact, the slag is only removed from the durations of the grate plate, but remains on the other parts of the grate plate. Often the slag sticks to the moving grate and moves back and forth with it until the air supply is clogged. In addition, cases are known where, because of the too long train of the movable grate, the complete ash, slag, fuel and embers are discarded from the grate plate, thus interrupting combustion.

Slightly better results in the incineration of slag-forming

The patent KR 100541280 describes fuels with the rust cleaning device with a cleaning comb moving between grate bars and carrying out a circular movement. This construction has the following disadvantages:

a. The plaster comb can not clean the surface of the grate bars, which lie directly between the leaves of the plaster comb.

b. All moving parts are in the combustion chamber at an extremely high temperature (over 1000 ° C), and therefore have a short

lifespan

c. All moving parts are in a room with the fuel and the ashes.

Thus, the ash not only falls under the rods, but also on the moving parts, such as sprockets, chain, axle, and drive, and causes intense wear.

From the patent KR 100901365 a disclosed by fuel and compressed air funnel flap is known, which serves to burn-back protection. The use of compressed air in the hopper is not desirable with light fuels (chips), since, firstly, it can cause the fuel to blow upward, and secondly introduces an uncontrolled additional amount of air into the combustion chamber.

From the patent JP 2000266333 a kiln is known, wherein the blowing out of ash through an opening in the bottom of the furnace is carried out by a downwards falling flap is opened. Such a construction does not allow the installation of a burner in a boiler with a lower burner door. because there is no free space under the burner.

From the patent US 1441293 a burner with two pistons is known. The lower piston is connected to a member of the sliding grate, wherein the primary air comes through an opening in the lower piston to the sliding grate. The upper piston is used for fuel refilling and is without air opening. Thus he becomes high

Temperatures loaded.

These problems are solved by the features listed in claim 1.

The advantages achieved by the invention are in particular that the embers and the melting ash, which lie on the grate, are stirred by the plaster comb. Thus, two effects are achieved: more complete combustion of the fuel and slag crushing before it has hardened. During the movement of the cleaning comb over the grate in the direction of the burner opening, the ash and the ski are discharged from the burner. According to the invention it is achieved that in the case that the slag adheres to the top of the grate bars, it is rubbed off during rotation of the grate bars of the plaster comb of the grate bar. The cleaning comb runs over the grille only in one direction to the burner opening, and under the grates, the movement of the

Burner opening back.

The feeding of the fuel to the grate bars by means of a piston. The piston closes in its stoppage the opening of the funnel, and thus forms the Rückbrandschutz.

The piston has at least one secondary air supply on the front side. Thanks to the air flowing through the piston, the piston and piston channel are cooled, thus preventing sticking of fuel particles.

Fuel slips through the hopper due to gravity, as the skid has an angle of incline that is greater than the angle of the natural fracture. The funnel of the fuel has a larger opening at the bottom than at the top. Thus, the funnel can not clog.

The funnel has a back fire damper flap, the suspension axis of which is arranged to rest the backfire damper on the slip wall. Thus, the backfire damper closes the funnel, and only opens when fuel presses from above.

All movable parts of the burner are located in zones of combustion air and are thus cooled.

An embodiment of the invention will be explained in more detail with reference to FIGS. Show it: FIG. 1 A burner according to the invention in side section with an eccentric shaft and a pendulum lug

Fig.2 burner seen from the burner opening, in partial section

Fig.3 Burner in the side section, with an eccentric shaft and a pendulum pocket, with cleaning comb and piston in standstill positions

Fig.4 Burner in the side section with two eccentric shafts

Fig.5 Part of the burner in side section with possible

Movements of the plaster comb

Fig.6 Seitenschniit the funnel with the funnel flap

Fig.7 cleaning comb and grate bars with the position of the cleaning comb below (standstill)

Fig.8 cleaning comb and grate bars with the top of the cleaning comb

Fig.9 Smashing and stirring the slag and ember layer

Fig.10 abrading the slag from the rotating grate bar through the plaster comb

The invention relates to a burner for the combustion of solid fuels, in particular, pellets and wood chips, which are also lower than standardized

May have ash melting temperature. The burner has at least two mutually parallel spaced parallel grate bars 25, under which primary air 26 flows. The grate bars 25 are next to each other between

Inner walls 1 of the burner positioned and in the openings in the

Burner flange 7 and stored on the grate carrier 24. The inner walls 1 have at least one opening 2 for secondary air 5. The inner walls 1 together with the outer walls 3 a channel for secondary air. 5

The grate bars 25 can be rotated by cooperation of the adhering to the grate bars slag particles and the moving cleaning comb 22 or the grate bars 25 can be rotated by a drive.

All moving parts are either under the grate bars 25, or in the channel between the inner wall 1 and outer wall 3, and are thus cooled by the primary air flowing through the grate 26, or by the secondary air 5 flowing through the channel.

The cleaning comb 22 is located at a standstill below the grate bars 25 and is cooled by the primary air 26 flowing through. The cleaning comb 22 makes the following movement: up through the grate bars 25, smashes lying on the grate bars 22 slag and glow layer 29, and passes through the on the grate bars 22nd Thereafter, the cleaning comb 22 moves in the direction of the burner opening, thereby carrying the slag 28 from the burner, then down under the grate bars, and finally in the direction of the

Burner flange 7. This movement of the cleaning comb 22 may also be circular.

The burner is closed by a burner cover 4 from above, which lies on the inner walls 1.

For mounting the burner to the boiler, or other device, the flange 7 serves as the flange. Most of the burner parts, e.g.

Flame detector 6; Ignition 17, to be attached.

The fuel, which is supplied to the hopper 8, falls by gravity to the opening in the piston channel 12, and is brought from the piston 1 1 on the grate bars 25.

The space with the Brennerteiien on the other side of the Brennerfiansches 7 is covered with a burner hood 10. The burner cap 10 is close to the

Burner flange 7 and funnel 8 mounted. The fan 13 is tightly mounted on the burner hood.

Rückbrandschutz is by closing the fuel port in the piston channel 12 by the piston 1 1 at a standstill, and from the hopper door 9 and

Fan flap 14 reached.

During the cleaning phase, the bottom slide 20 opens, and the ash that has fallen onto the burner bottom 30 between the grate bars 25 is blown by the fan 13 through the opening in the bottom 30.

FIGS. 1 and 2 show the burner in side section and in view of the burner opening. The plaster comb 22 is of an eccentric shaft and a

Pendelasche 18 moves. The eccentric of the plaster comb 22 and of the

Pendulum pocket 18 are offset about the axis of the eccentric shaft 16. Thus it is achieved that when the right part (on the picture) of the plaster comb 22 is at the top, the

Pendeilasche 18 is rotated to the right, and the Pendeiachse 19 raises the left part (on the picture) of the plaster comb upwards.

Fig. 3 shows the burner in side section, with an eccentric shaft 16 and a pendulum lug 18, with cleaning comb 22 and piston 10 in standstill positions. For the cleaning comb 22 is the standstill position under the grate bars 25, where the primary air cools the plaster comb 22. For the piston 10, the stoppage position is the end point toward the burner port (as shown in the picture).

4 shows the burner in side section with two eccentric shafts 16 and 27, which dictate the movement of the cleaning comb 22. Fig. 5 shows parts of the burner (cleaning comb 22 and grate bars 25), and the possible movements of the plaster comb 22nd

FIGS. 7 and 8 show parts of the burner (cleaning comb 22 and grate bars 25) in side section and the positions of the cleaning comb 22 below (FIG. 7) and (FIG. 8) the grate bars 25.

FIG. 6 shows a side section of the funnel 8 with the funnel flap 9 in the closed state (FIG. 6a); in the open state (FIG. 6B) and the vector of gravity in the open state (FIG. 6c).

Fig. 9 shows the smashing and stirring of the slag and ember 29, which lies on the grate bars 25, through the plaster comb 22 during its upward movement. Fig. 9a shows the plaster comb 22 at a standstill under the grate bars 25 before the beginning of its movement upwards. FIG. 9b shows the plaster comb 22 over the grate bars 25 after having agitated the slag and ember layer 29.

10 shows the slag 28 adhering to the upper side of the grate bar 25, FIG. 10b shows the grate bar 25 already turned, Fig. 10b shows the slag 28 adhered to the grate bar 25 adhering to the grate bar 25 10c shows the slag 28 already rubbed off the grate bar 25 and the cleaning comb 22 in the position above the grate bar 25.

Claims

Patent claims:

1. Burner for the combustion of solid fuels, in particular pellets and wood chips, with at least two grate bars (25) arranged parallel to one another between the inner walls (1) of the burner at a mutual distance, which are in openings in a burner flange (7) and on a grate support (24). are stored, characterized in that between the grate bars (25) a cleaning comb (22) makes the following movement: upwards through the

Grate bars (25), then towards the burner opening, then down under the grate bars, and finally towards the burner flange (7), with fuel sliding down in a funnel (8) due to gravity, a funnel flap (9) opens, and from a piston (1 1), which has at least one opening (15) for secondary air (5), which also ensures the cooling of the piston (1 1) and the piston channel (12), is pushed onto the grate bars (25), Ash that has fallen under the grate bars (25) on a burner base (30) is blown out by a fan (13) through a cutout in the burner base (30) opened by a base slide (20).

2. Burner according to claim 1, characterized in that the grate bars (25) are mounted in a freely rotating manner and are rotated by the interaction of the slag particles adhering to the grate bars (25) and the moving cleaning comb (22).

3. Burner according to claim 1, characterized in that the grate bars (25) are mounted in a rotating manner and are rotated by means of a drive.

4. Burner according to one of claims 1 to 3, characterized in that the movement of the cleaning comb (22) is circular.

5. Burner according to one of claims 1 to 4, characterized in that the cleaning comb (22) is composed of an eccentric shaft (16) with two eccentrics offset about an axis of the eccentric shaft and a pendulum bracket (18).

Pendulum axis (19) is moved.

6. Burner according to one of claims 1 to 4, characterized in that the cleaning comb (22) is moved by two eccentric shafts (16) and (27).

7. Burner according to one of claims (1) to (6), characterized in that the funnel (8) has the shape of a leaning pyramid, which has a larger opening at the bottom than at the top and a receiving axis of the funnel flap (9) is arranged in this way that the funnel flap (9) comes to rest on a sliding wall due to its own weight, the sliding wall having such a

Has an angle of inclination to allow the fuel to slide off.

8. Burner according to one of claims 1 to 7, characterized in that all moving parts are located under the grate bars (25) and / or between inner walls (1) and outer walls (3) in zones through which air flows. Pos. Description

1 interior wall

2 opening for secondary air

3 external wall

4 burner cover

5 secondary air

6 flame detector (e.g. photo sensor)

7 burner flange

8 funnels

9 funnel flap

10 burner hood

1 1 piston

12 piston canai

13 fan

14 fan flap

15 air opening in the piston

16 eccentric shaft

17 ignition unit

18 pendulum strap

19 pendulum axle

20 floor sliders

21 axis guide

22 cleaning comb

23 grate bar supports

24 locking platies

25 rotating grate bar Primary air

Eccentric shaft two

slag

Slag and waste layer

Burner base