DE102013215429A1 - Apparatus for drying bulk solid biomass and biomass gasification plant - Google Patents

Abstract

The present invention provides a device (1) for drying bulk material (59), in particular woodchips, comprising a container (2) and a channel (10) which extends inside the container (2) and divides it into two chambers (11 , 12) for receiving the biomass (59), wherein side walls (31, 32) of the channel (10) openings (43), by means of which a respective chamber (11, 12) a drying gas (42) for drying the therein received Biomass (59) can be fed.

Description

The present invention relates to a device for drying bulk solid biomass and a biomass gasification plant.

Biomass gasification plants, such as wood gasification plants, have been known since the end of the 19th century. Modern wood gasification plants comprise a gasifier for producing fuel gas from wood, in particular wood chips. The wood is converted by a pollination with air in the fuel gas, in particular carbon monoxide and methane. Furthermore, such wood gasification plants comprise a combined heat and power plant. This generates combustion of the fuel gas, for example, in an internal combustion engine, electrical energy and heat. By using both forms of energy such wood gasification plants can have a high efficiency, for example, of over 80%.

In view of a high efficiency, it has been found to be favorable, the biomass dry biomass, for example, with a residual moisture content <10%, supply. Therefore, it has become known to dry the wood, in particular the wood chips, before they are supplied to the gasifier.

It is an object of the present invention to provide an improved apparatus for drying bulk solid biomass.

This object is achieved by a device for drying bulk material-shaped biomass, in particular wood chips, with a container and a channel. The channel extends within the container and divides it into two chambers for receiving the biomass. Side walls of the channel have openings, by means of which a drying chamber for feeding the biomass received therein can be fed to a respective chamber.

The fact that the drying gas flows laterally into a respective chamber, a dust discharge is reduced from the device. For if the drying gas flows from below into the chamber, it ruptures on its way upwards, in particular dust adhering to woodchips, and carries it upwards out of the device, which is due not least to the rapid rise of hot gases. By contrast, if a respective chamber flows through laterally, that is to say horizontally, then the flow velocity of the drying gas in this direction is slower, so that less dust is discharged from the device. In addition, due to its slower flow rate, the drying gas stays in contact with the biomass for a longer period of time, thus improving drying. In other words, a higher moisture saturation of the drying air is achieved.

In addition, the biomass can be dried evenly by means of the lateral openings.

The container may for example have four side walls, which are arranged rectangular in a plan view. Furthermore, the container may have a rectangular bottom which closes the space enclosed by the side walls at the bottom - optionally excluding a slot for removing dried biomass. Furthermore, the container may have a lid which closes the said interior space at the top. The side walls, the bottom and / or the lid can be made as sheet metal parts. The container may have a trapezoidal cross-section.

The channel may have side walls, a roof and / or a floor. The channel may have a cross section which is composed of a trapezoid and a triangle.

The biomass may, for example, be wood, in particular wood chips.

For example, hot air, in particular with a temperature above 20 °, preferably above 45 °, can be used as the drying gas. The drying gas may be warm air, which is generated by a heat exchanger that uses waste heat from the cogeneration unit of the biomass gasification plant. Furthermore, warm air can be used as a drying gas from a machine room which receives the internal combustion engine of the combined heat and power plant. Furthermore, alternatively or additionally, the exhaust gas of the internal combustion engine can be used as a drying gas.

According to one embodiment, a respective chamber is bounded in each case by a side wall of the container, wherein the side walls have openings, by means of which the drying gas can be led out of a respective chamber.

The drying gas thus flows from the openings in a side wall of the channel to the opposite openings in the side wall of the container. The drying gas flows in a horizontal direction through the biomass. Through the openings in the side walls of the container, the drying gas can be discharged, for example, to the environment.

For example, more than ten openings or more than fifty openings may be provided in a respective side wall of the channel or container. At least, however, is an opening intended. The openings are preferably formed as holes, in particular circular holes.

According to a further embodiment, the openings in a respective side wall of the channel and / or container are arranged one above the other.

By distributed in the vertical direction openings a more uniform drying in the vertical direction is achieved. The distance between the openings, in particular holes, can increase from bottom to top. As the drying gas rises, it is in the interests of a more uniform drying advantage, this stronger in the lower area, ie with a higher volume flow to initiate.

As far as reference is here made to a "respective side wall" of the container, at least one side wall of a respective chamber is meant. For example, these side walls are the long sides of the container. Side walls at the end faces of the container, which may also define a respective chamber, may be formed without openings.

According to a further embodiment, a respective side wall of the container has at least two Z-shaped wall elements, each having an upper and a lower portion and a connecting portion, wherein the upper portion of a Z-shaped wall element against the lower portion of the other Z- shaped wall element rests and openings in these wall sections to form an opening in the corresponding side wall are aligned.

In other words, at least one opening in the upper section is aligned with at least one opening in the lower section. This results in a continuous outlet through which the drying gas can be led out of the chamber through the side wall of the container. Preferably, the lower and upper portions each have a plurality of openings which are aligned with each other. In addition, the side walls of the container preferably each comprise more than two Z-shaped wall elements. The wall elements may be formed as sheet metal parts.

A respective Z-shaped wall element may define a corner region of the chamber, which widens the interior of the chamber in a jagged manner towards the top. The continuous outlet is at the upper end of the corner region, for example. In an upper third thereof, so that a gravity-induced discharge of dust and small parts from the continuous outlet, as well as a blockage thereof, is prevented.

According to a further embodiment, the side walls of the channel and the container are arranged such that a respective chamber widens downwards.

This prevents bridging of the biomass. By "bridging" is meant an internal cohesion of the biomass, in particular the wood chips, such that a subset thereof can not be detected by a gravity-assisted discharge device for discharging the dried biomass from the device, such as a rake, so that this subset remains in the device.

According to another embodiment, an angle which a side wall of the channel forms with the vertical is not equal to an angle which forms a side wall of the container with the vertical.

Due to the different angles, the formation of bridges is even better counteracted.

According to a further embodiment, the device is set up so that the drying gas flows through a respective chamber horizontally.

The horizontal flow preferably takes place in a direction perpendicular to the direction of flow of the drying gas into the channel.

According to a further embodiment, the device is set up so that the drying gas flows into the channel in the longitudinal direction thereof.

Accordingly, the gas in the channel is deflected in the transverse direction to flow out of the openings in the side walls of the channel.

According to a further embodiment, the channel has on its one end face a connection for supplying the drying gas. The connection may be rectangular in shape. A transition piece, which connects a hose for supplying the drying gas to the port, can fan out.

According to a further embodiment, the channel is formed closed at its other end side.

According to a further embodiment, a discharge device, in particular a rake, for discharging the biomass is arranged at the bottom of a respective chamber.

The device may have one, two or more rakes. For example, two rakes can be provided, one rake each being arranged at the bottom of a respective chamber. The one or more rakes are adapted to bring out the biomass in the longitudinal direction, ie horizontally out of the container. For this purpose, the container may have a respective slot above the bottom. For conveying out a respective rake, for example, by means of a hydraulic back and forth moves. Instead of a rake, another discharge device, for example a spiral conveyor, could also be provided.

According to another embodiment, the rake has fixed and movable wedge elements.

The movable wedge elements can be actuated in particular via a rod. The rod may in turn be coupled to a hydraulic cylinder for advancing and retracting the wedge members.

According to a further embodiment, the height of the wedge elements increases in the conveying direction. This ensures a more even discharge of the biomass from the container. For with wedge elements of the same height, would be at the end of a particular rake, which is remote from the discharge, in particular the discharge slot, result in less wood chips, which would be accompanied by a corresponding loss of air and thus a reduced drying effect.

According to a further embodiment, the channel extends to the bottom and / or between two discharge devices, in particular two rakes.

This results in a simple structure.

According to a further embodiment, an axisless spiral conveyor system is provided, by means of which the biomass conveyed out from the rake can be conveyed in the direction of a carburetor.

This also includes an indirect feeding: Thus, the biomass, for example, by means of the spiral conveyor initially be fed to a screening plant. From there, it is fed to a storage container and, for example, only then to the carburetor.

According to a further embodiment, the container has a lid, which closes a respective chamber in a closed position of a gas-tight upwardly and in an open position thereof an access to a respective chamber for filling the same releases with biomass.

Furthermore, a biomass gasification plant, in particular a wood gasification plant, with a device as described above, a gasifier for producing fuel gas from the dried biomass and a combined heat and power plant for generating electrical energy and heat combustion of the fuel gas is provided.

Further advantageous embodiments and aspects of the invention are the subject of the dependent claims and the embodiments of the invention described below. Furthermore, the invention will be explained in more detail by means of preferred embodiments with reference to the attached figures.

1 shows in a perspective view a device according to an embodiment;

2 shows a view II 1 ;

3 shows a view III 1 ;

4 shows a plan view 1 ;

5 shows in a perspective view of a frame of the device 1 ;

6 shows in a perspective view of a Z-shaped plate 1 ;

7 schematically shows a partial section 1 ;

8th shows in perspective a channel of the device 1 ;

8A shows a side view 8th ;

9 shows in perspective a floor frame including rake of the device 1 ;

10 shows a rake 9 in a side view;

10A shows a schematic diagram;

11 shows in a perspective view of an axisless spiral conveyor of the device 1 which is not shown there.

In the figures, like reference numerals designate like or functionally identical elements, unless indicated otherwise.

1 shows a device 1 for drying wood chips 59 (please refer 7 ). The contraption 1 includes a container 2 , The container 2 has opposite, longitudinal side walls 3 . 4 and opposite, front side walls 5 . 6 on. As in 4 to recognize, are the side walls 3 to 6 seen in a plan view arranged rectangular. In addition, the container includes 2 a floor 7 and a lid 8th , The side walls 3 to 6 , the floor 7 and the lid 8th (when closed) thus define an interior 9 of the container.

The device 1 also has a channel 10 on. The channel 10 divided the interior 9 in two chambers 11 . 12 , such as in 4 to recognize. The channel 10 is by means of a transition piece 13 and a subsequent thereto, not shown tube supplied to a drying gas. The transition piece 13 fans in the direction of the canal 10 on, like in 2 to see.

The lid 8th is for example via a hydraulic system 14 from the in 3 shown open position in a closed position adjustable, in which he the interior 9 closes gas-tight at the top. In the opened state of the lid 8th become the chambers 11 . 12 with chips 59 filled. The filling can be done for example by means of a shovel loader. After filling the chambers 10 . 11 becomes the lid 8th closed. Also down is the container 2 gas-tight closed, except for two discharge slots 15 . 16 above each one on the ground 7 movably provided rake 17 . 18 ,

The floor 7 rests on feet 17 on the unspecified soil from.

After this overview over the device 1 , now in conjunction with the other figures, a more detailed description.

5 shows a frame 19 the device 1 , This is made by example with 20 to 22 termed struts together. The aspiration 20 to 22 are, for example, as profile parts, in particular U- or H-profiles, made of steel. To make the sidewall 3 for example, between two U-profiles 20 . 21 in 6 shown, Z-shaped sheets 23 inserted. A respective Z-shaped sheet metal 23 includes an upper section 24 , a lower section 25 and a connecting section 26 , The upper section 24 and the lower section 25 each have a variety of holes 27 . 28 on, as well as in 7 to recognize. As in further 7 shown, the sheets are 23 in the U-shaped profiles 20 . 21 inserted, in such a way that a lower section 25 a Z-shaped sheet 23 ' on an upper section 24 an underlying Z-shaped sheet metal 23 rests. The holes 27 . 28 in the upper or lower section 24 . 25 then align and form an opening together 29 (also referred to as outlet) for leakage of drying gas 42 out of the chamber 11 in the nearby areas 30 ,

8th shows the channel 10 in partially transparent representation. The channel 10 includes side walls 31 . 32 , a roof 33 and a floor 34 (please refer 9 ). A front page 35 of the canal 10 includes an inlet opening 36 for a flow of drying gas in the longitudinal direction 37 of the canal 10 , The other front side 38 of the canal 10 is closed. The roof 33 has a triangular shape. From the top of the canal 10 falling wood chips 59 thus slide into the chambers 11 . 12 from. The side walls 31 . 32 due to their oblique orientation together define a trapezoidal channel cross-section 49 , as explained in more detail below. Because of the badger 33 becomes the channel cross section 49 supplemented by a triangle at the top. Within the channel 10 are support plates 39 arranged, which the side walls 31 . 32 as well as the roof 33 support. The channel 10 is via consoles 40 at cross struts 41 held, which in turn to upper struts 22 of the frame 19 (please refer 5 ).

Now returning to 7 , there is the channel 10 partially shown, in cross section. The drying gas 42 flows in the longitudinal direction 37 (please refer 8th ) in the channel 10 one, ie in the horizontal direction, and flows from there through openings 43 perpendicular to the longitudinal direction 37 and in the horizontal plane through the with the wood chips 59 filled chamber 11 and then through the openings 29 out of the chamber 11 out in the area 30 ,

Because the lid 8th the container 2 closes gas-tight at the top, is the drying gas 42 forced, laterally and thus slower through the wood chips 59 to flow, resulting in an improved drying effect. In addition, so is the dust discharge from the container 2 minimized.

The openings 43 form one in 8A shown hole pattern, wherein a plurality of openings 43 longitudinal 37 one after the other and in the vertical direction 44 are arranged one above the other. The distance between the openings 43 increases in the vertical direction, as in 8A indicated. The distance is there with 45 respectively. 45 ' designated.

Furthermore, in 7 recognizable that the Z-shaped sheets 23 are arranged so that they are the chamber 11 each around a serrated corner area 46 expand. The opening 29 is in the area of the upper end of the corner area 46 provided so that by gravity no dust or the like through the opening 29 can escape or a blockage of the opening 29 through wood chips 59 is avoided.

In 7 is further shown that the side wall 31 of the canal 10 an angle 47 with the vertical forms. Furthermore, the side wall forms 3 an angle 48 with the vertical. The angles 47 . 48 are such that the chamber 11 extended downwards. Besides, the angle is 47 unlike the angle 48 , which counteracts the formation of bridges. Furthermore, the angle 47 preferably chosen so that the side wall 31 to the side wall 3 tends towards, so the channel cross-section 49 expanding to the top.

The explanations related to 7 apply accordingly to the side wall 32 of the canal 10 as well as the side wall 4 of the container 2 ,

Based on 9 . 10 and 10A Below is the operation of the rake 17 . 18 explained in more detail.

Everyone's rake 17 . 18 includes fixed wedge elements 50 and movable wedge elements 51 , The following explanations refer to the rake by way of example 17 , but apply to the rake 18 corresponding. The movable wedge elements 51 are with a pole 52 firmly connected. The pole 52 is again via a hydraulic system 53 movable back and forth. The fixed wedge elements 50 are stuck with a U-shaped sheet metal 54 connected. The fixed wedge elements 50 are each in pairs across the conveying direction 55 arranged side by side and over a loop 56 connected with each other. Through the loops 56 is the rod 52 guided. The movable wedge elements 51 are in pairs across the conveying direction 55 on both sides of the pole 52 arranged and firmly connected with this. 10 shows the movable wedge elements 51 in their foremost position. Will the pole now 52 moved back by means of hydraulic, it forms between two wedge elements 50 . 51 a gap in which wood chips 59 fall in. With the move forward, the chips become 59 then in the conveying direction 55 through the discharge slot 15 brought out and into an in 11 shown axisless spiral conveyor 57 moved in which the wood chips 59 then, for example, a screen or a storage container supplies. The axleless spiral conveyor 57 promotes the wood chips 59 transverse to the conveying direction 55 from. Finally, the wood chips arrive 59 to a carburetor (not shown). The fuel gas generated in the gasifier is used to operate a cogeneration unit, not shown.

Now returning to 10 it can be seen that thrust surfaces 58 the wedge elements 50 . 51 one in the conveying direction 55 increasing height 60 exhibit. This avoids that in 10A shown problem. In 10A are wedge elements 50 . 51 with shear surfaces 58 same height 60 shown. This will make the chips 59 over the length of the rake 17 (The length refers to the conveying direction 55 ) unevenly discharged, so that the drying air 42 in the back of the rake 17 less wood chips 59 "Sees" and thereby escapes faster in this area. A drying of the wood chips 59 in the front area of the rake 17 is deteriorating.

In 9 is further to realize that the two rake 17 . 18 are arranged side by side, with the ground between them 34 of the canal 10 extends. The floor 34 comes with the sidewalls 31 . 32 (please refer 8th ) of the channel 10 connected gas-tight during installation. The floor 34 as well as the sheets 54 the rake 17 . 18 are with the ground 7 firmly connected, in particular welded.

Although the invention has been described with reference to embodiments herein, it is variously modifiable.

LIST OF REFERENCE NUMBERS

1

 contraption

2

 container

3

 Side wall

4

 Side wall

5

 Side wall

6

 Side wall

7

 ground

8th

 cover

9

 inner space

10

 channel

11

 chamber

12

 chamber

13

 Transition piece

14

 hydraulic

15

 discharge slot

16

 discharge slot

17

 rake

18

 rake

19

 frame

20

 strut

21

 strut

22

 strut

23

 Z-shaped sheet metal

24

 section

25

 section

26

 section

27

 hole

28

 hole

29

 opening

30

 Surroundings

31

 Side wall

32

 Side wall

33

 top, roof

34

 ground

35

 front

36

 inlet port

37

 longitudinal direction

38

 front

39

 gusset

40

 console

41

 crossmember

42

 drying gas

43

 opening

44

 vertical direction

45

 distance

45 '

 distance

46

 corner

47

 angle

48

 angle

49

 Channel cross section

50

 key member

51

 key members

52

 pole

53

 hydraulic

54

 sheet

55

 Conveyor

56

 loop

57

 axisless spiral conveyor

58

 pushing surface

59

 wood chips

60

 height

Claims (15)

Contraption ( 1 ) for drying bulk solid biomass ( 59 ), in particular of wood chips, with a container ( 2 ) and a channel ( 10 ) located inside the container ( 2 ) and this into two chambers ( 11 . 12 ) for receiving the biomass ( 59 ), whereby side walls ( 31 . 32 ) of the channel ( 10 ) Openings ( 43 ) by means of which a respective chamber ( 11 . 12 ) a drying gas ( 42 ) for drying the biomass absorbed therein ( 59 ) can be fed. Device according to claim 1, wherein a respective chamber ( 11 . 12 ) of each side wall ( 3 . 4 ) of the container ( 2 ) and the side walls ( 3 . 4 ) Openings ( 29 ), by means of which the drying gas ( 42 ) from a respective chamber ( 11 . 12 ) is herausführbar. Device according to claim 1 or 2, wherein the openings ( 43 . 29 ) in a respective side wall ( 31 . 32 ) of the channel ( 10 ) and / or a respective side wall ( 3 . 4 ) of the container ( 2 ) are arranged one above the other. Apparatus according to claim 2 or 3, wherein a respective side wall ( 3 . 4 ) of the container ( 2 ) at least two Z-shaped wall elements ( 23 . 23 ' ), each having an upper and a lower portion ( 24 . 25 ) and a section connecting them ( 26 ), wherein the upper portion ( 24 ) of a Z-shaped wall element ( 23 ) against the lower section ( 25 ) of the other Z-shaped wall element ( 23 ' ) and openings ( 27 . 28 ) in these sections ( 24 . 25 ) for forming a respective opening ( 29 ) in the corresponding side wall ( 3 . 4 ) are aligned with each other. Device according to one of claims 2-4, wherein the side walls ( 31 . 32 ) of the channel ( 10 ) and the side walls ( 3 . 4 ) of the container ( 2 ) are arranged such that a respective chamber ( 11 . 12 ) widened downwards. Apparatus according to claim 5, wherein an angle ( 47 ), which has a side wall ( 31 . 32 ) of the channel ( 10 ) with the vertical, unlike an angle ( 48 ), to which a side wall ( 3 . 4 ) of the container ( 2 ) with the vertical forms. Device according to one of claims 1-6, which is arranged such that the drying gas ( 42 ) a respective chamber ( 11 . 12 ) flows through horizontally. Device according to one of claims 1-7, which is arranged such that the drying gas ( 42 ) into the channel ( 10 ) longitudinal ( 37 ) flows in the same. Device according to one of claims 1-8, wherein the channel ( 10 ) on its one end face ( 35 ) a connection ( 36 ) for supplying the drying gas ( 42 ) and / or on its other end face ( 38 ) is closed. Device according to one of claims 1-9, wherein on a ground ( 61 ) of a respective chamber ( 11 . 12 ) a discharge device, in particular a rake ( 17 . 18 ), to promote the biomass ( 59 ) is arranged. Apparatus according to claim 10, wherein the rake ( 17 . 18 ) fixed and movable wedge elements ( 50 . 51 ) and / or wherein the height ( 60 ) of the wedge elements ( 50 . 51 ) in the conveying direction ( 55 ) increases. Apparatus according to claim 10 or 11, wherein the channel ( 10 ) to the ground ( 61 ) and / or between two discharge devices, in particular two rakes ( 17 . 18 ) extends. Device according to one of the claims 10-12, wherein an axisless spiral conveyor ( 57 ) is provided, by means of which the of the rake ( 17 . 18 ) extracted biomass ( 59 ) is conveyed in the direction of a carburetor. Device according to one of claims 1-13, wherein the container ( 2 ) a lid ( 8th ), which in a closed position of the same a respective chamber ( 11 . 12 ) closes gas-tight at the top and in an open position of the same an access to a respective chamber ( 11 . 12 ) for filling it with biomass ( 59 ) releases. Biomass gasification plant, in particular wood gasification plant, with a device ( 1 ) for drying bulk solid biomass ( 59 ) according to any one of claims 1-14, a gasifier for producing fuel gas from the dried biomass and a combined heat and power plant for generating electrical energy and heat under combustion of the fuel gas.

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