DE102013215431B4 - Filter device, biomass gasification plant and use of an armor as a filter medium - Google Patents

Abstract

Filter device (8) for filtering fuel gas generated by gasification of biomass, comprising a filter body (11) having a filter medium (23) formed as a fabric (23), wherein the fabric (23) is formed as an armor.

Description

The present invention relates to a filter device for filtering fuel gas produced by gasification of biomass, a biomass gasification plant and the use of an armor as a filter medium.

Biomass gasification plants, in particular wood gasification plants have been known since the end of the 19th century. Wood gas is produced, for example, when heating wood, in particular wood chips. This usually happens in a carburetor. Before the wood gas is supplied to a cogeneration plant for the production of electrical energy and heat, the wood gas must be filtered. This especially to avoid damage to the internal combustion engine used. But also to protect the environment, it is necessary to filter the wood gas. In the way of filtering unwanted organic substances are removed in particular from the wood gas.

For filtering, it is known to use surface filters. In contrast to depth filters, the actual separation effect is not caused by the filter medium but by a filter cake that forms on the surface of the filter.

For example, is from the DE 10 2010 037 768 A1 a filter device for filtering wood gas is known which provides a stainless steel fleece as the filter medium. It has been found that stainless steel nonwovens have different properties across their surface. As a result, such nonwovens locally wear to varying degrees and accordingly a deposition varies locally. Filter devices with stainless steel nonwovens therefore tend to be less reliable in terms of the degree of separation achieved, and must be partially replaced, in part only because of local wear.

The EP 0 855 207 B1 relates to a filter element. A filter material may consist of a metal fabric, in particular stainless steel.

The WO 2009/013005 A1 describes a fine dust filter. Filter cartridges use stainless steel mesh.

AT 504 124 B1 and DE 103 00 406 A1 describe armor tears when sifting plastics.

The object of the present invention is therefore to provide an improved filter device which has a longer service life.

This object is achieved by a filter device for filtering fuel gas produced by gasification of biomass, comprising a filter body having a filter medium which is formed as a tissue, wherein the tissue is designed as an armor.

A woven fabric, in particular a stainless steel mesh, has more uniform properties over a stainless steel fleece over its surface, which is due to the regular arrangement of warp and weft threads in a woven fabric. Thus, the fabric wears uniformly, and the degree of separation achieved is the same across the surface of the fabric. Therefore, the filter device must be replaced only when the fabric is worn out altogether, resulting in a longer life.

The fabric is preferably provided exclusively in one layer.

For example, wood, in particular wood chips, horse manure, fermentation residues, sewage sludge or any other gasifiable material can be used as the biomass.

In the case of wood, the fabric preferably has a heat resistance of up to 950 °. In the case of biomass except wood, the fabric preferably has a heat resistance of up to 650 °, where it is also possible to use up to 950 ° heat-resistant material.

According to one embodiment, the fabric has a wire diameter of 20-100 μm, in particular 30-60 μm.

As a result, a suitable filter cake can be produced, which filters out particles smaller, for example, 5-15 μ, preferably less than 8-10 μ, from the fuel gas. Such filtered fuel gas is typically suitable for internal combustion engines.

The fabric is woven as an armor tatter. An armor is a particularly stable type of fabric.

The filter body preferably has a cylindrical shape with an annular base. The filter body may for example have an outer diameter of between 100 and 200 mm, preferably between 130 and 170 mm. The filter body may for example have a height of 800-1400 mm, preferably 1100-1300 mm.

According to a further embodiment, the fabric comprises a stainless steel mesh and / or a nickel-iron alloy.

Stainless steel mesh is particularly heat resistant. The alloy may contain, for example, the following percentages by weight: 30-35% nickel, 19-23% chromium and at least 39.5% iron.

According to a further embodiment, the filter body has a first support material arranged within the filter medium, which is set up to support the filter medium against a pressure difference applied in filter operation of the filter device for filtering the generated fuel gas.

This prevents the filter medium from collapsing during filter operation. In filter operation, the filter device filters the fuel gas generated by the carburetor.

According to a further embodiment, the first support material is a perforated plate.

Holes in the perforated plate may be, for example, round or rectangular. A diameter or an edge length of such a hole may for example be between 1 and 15 mm.

According to a further embodiment, the filter body has a second support material arranged outside the filter medium, which is set up to support the filter medium against a pressure difference present in the backwashing operation of the filter device.

The filter device must be backwashed regularly to prevent the filter cake from becoming too large and ultimately impairing filtering.

According to a further embodiment, the second support material is designed as a support wire.

The support wire may be spirally wound around the filter medium.

According to a further embodiment, the filter body has a protective material which is arranged between the first support material and the filter medium and / or the filter medium and the second support material.

Thus, for example, a first and a second protective material may be provided. The first protection material may be disposed between the first support material and the filter medium and the second protection material may be disposed between the filter medium and the second support material.

According to a further embodiment, the protective material is a protective fabric, in particular a stainless steel fabric. The protective material may comprise wires with a wire diameter of, for example, greater than 200 μm.

According to a further embodiment, the filter body is fastened by means of a collar to a flange for attachment of the filter device to a filter housing.

In particular, the filter device can be hung with its flange in the filter housing from above. The flange may be disposed at one end of the filter body.

According to a further embodiment, the filter body is formed closed at one end. Additionally or alternatively, a plate bottom is disposed within the filter body for reinforcement thereof.

In particular, the plate floor can be connected to the first support material. The plate bottom can be arranged at one end of the filter body. The plate bottom may be disposed at one end of the filter body opposite the flange. The plate bottom can have a U-shaped cross-section. The plate bottom closes the filter body at one end.

According to a further embodiment, the filter medium is welded to the first support material, the second support material and / or the protective material.

The corresponding one or more welds may be punctiform. Further, the welds, even punctiform, along a line, for example, be arranged parallel to the central axis of the filter body. The one or more weld seams can be designed so that they connect in the radial direction in each case the filter medium, the first support material, the second support material and / or the protective material together materially.

Furthermore, a biomass gasification plant, in particular in a wood gasification plant, provided with a filter device as described above.

Further, a method of replacing the filter medium in the above-described filter device is provided. According to the method, the second support material or the protective material is cut open and the filter medium is subsequently exchanged.

The cutting will expose access to the filter medium for replacement. When cutting any welds or welds are mitzertrennt or by pulling down the second Stützmateri- or demolished the protective material.

The features intended for the filter device apply mutatis mutandis to the biomass gasification plant and the method, and vice versa.

In the present case, "a" does not exclude a large number.

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 schematically shows a wood gasification plant according to an embodiment;

2 shows in a sectional view of a filter device of a filter 1 ;

3 shows a view III 2 ;

4 shows an enlarged view IV 2 ; and

5 shows a schematic section VV 4 ,

In the figures, the same or functionally identical elements have been given the same reference numerals, unless stated otherwise.

1 shows a biomass gasification plant 1 which is a carburetor 2 , a filter 3 and a combined heat and power plant 4 includes.

In the carburetor 2 Biomass, such as wood chips, horse manure or Geerereste, gasified with the supply of heat. This results in a fuel gas, which in the case of gasification of wood has a temperature of for example 850-950 ° and in the case of gasification of biomass containing no wood, a temperature of 550 and 650 °, for example. This fuel gas comprises undesirable organic substances which are contained in a filter 3 be filtered out.

The filter 3 includes a filter housing 5 , Between a raw page 6 and a clean side 7 of the filter 3 are several filter devices 8th intended. These can, for example, in a perforated plate 9 be hooked.

The filter devices 8th are designed as surface filters, so that forms on these a filter cake, which takes over the actual filter task. The fuel gas filtered in this way preferably has no particles greater than 8 μ. The fuel gas flows to the filter 3 in an internal combustion engine 10 of the combined heat and power plant 4 and is burned there releasing heat and mechanical energy. The mechanical energy is used to drive a generator to generate electrical power. The heat can be fed into a local heating network.

Based on 2 - 5 Below is the removal of the filter device 8th using a filter device 8th exemplified.

The filter device 8th has a filter body 11 on. The filter body 11 can be cylindrical with an annular base.

Furthermore, the filter device comprises 8th a collar 12 and a flange 13 , The filter body 11 is at its one end 14 with the collar 12 and this in turn with an inner surface 15 of the flange 13 welded. The flange 13 can have several holes 16 for screwing the same with, for example, the perforated plate 9 (please refer 1 ) exhibit.

At the opposite end 17 of the filter body 11 is a plate floor 18 used in these. The plate floor 18 has a cross-section, for example, U-shaped shape. The plate floor 18 can with the filter body 11 be welded on the inside. Especially the plate floor 18 is an optional element, which can be omitted. The end 17 could otherwise be designed as closed, for example by means of a dished bottom.

Both the collar 12 as well as the plate floor 18 stabilize the filter body 11 and serve in particular the maintenance of its cylindrical shape. The collar 12 and the plate floor 18 can be made of stainless steel sheet. As a material, for example, X15CrNiSI20-12 (also known as ST 1.4828) into consideration. As a welding process to the filter body 11 with the collar 12 or the plate floor 18 with the filter body 11 To weld, in particular plasma welding is used.

By way of example, the filter device may have a height H of between 1000 and 1500 mm, preferably 1200-1300 mm. An outer diameter D1 of the filter body 11 may for example be between 100 and 200 mm, preferably between 150 and 160 mm. An outer diameter D2 of the filter device 8th , in particular of the flange 13 , for example, may be between 200 and 300 mm, preferably between 230 and 250 mm.

The structure of the filter body 11 is described below by means of 4 and 5 explained in detail. The filter body 11 has as the innermost layer a first support material in the form of a perforated plate 19 on. The perforated plate 19 includes holes 20 which may be square or round, for example. An edge length of the hole 20 or a diameter of the hole 20 may for example be between 5 and 15 mm. The perforated plate 19 is preferably also made of stainless steel, in particular X15CrNiSI20-12.

Radial outward - radial here refers to a central axis 21 of the filter body 11 followed by a layer of a first protective fabric, for example in the form of a stainless steel mesh 22 ,

Further radially outward now follows a filter medium 23 in the form of a fabric, in particular stainless steel fabric. The filter medium 23 is exactly single layered. The filter medium is, for example, a nickel-iron alloy with the following percentages by weight 30-35% nickel, 19-23% chromium and at least 39.5% iron. A suitable stainless steel mesh 23 is, for example, ST1.4876 (also under the name Incoloy ^® known) was prepared. The stainless steel mesh 23 is preferably woven as an armor tatter. A wire diameter of stainless steel fabric 23 is preferably between 30 and 70 microns, preferably between 55 and 65 microns.

Further radially outward is a second protective fabric 24 especially made of stainless steel. The first and second protective fabric 22 , Wires have a wire diameter preferably greater than 200 microns. Outside is the second protective fabric 24 a second support material in the form of a support wire 25 wound. For example, the support wire is spirally around the protective fabric 24 wound.

In 5 the individual components are shown schematically, esp. Size ratios do not correspond to reality. 5 shows a way of attaching the various layers together to the filter body 11 to build. According to the embodiment, multiple welding points 26 provided along a longitudinal axis which extends from top to bottom parallel to the central axis 21 extends. It is through all layers 24 . 23 . 22 and 19 by welded. Also the support wire 25 can be fixed in this way.

Is the filter medium 23 worn or needs to be replaced for other reasons become the support wire 25 and the second protective fabric 24 sliced, unwound and removed, including the welds 26 be separated. This is the access to the filter medium 23 released, which is also cut open and removed. After that, a new filter medium 23 , a (new) protective fabric 24 and a (new) support wire 25 again provided and the welds 26 renewed to return to an operable filter body 11 to obtain.

The perforated plate 19 prevents collapse inside the filter medium 23 when dealing with the differential pressure between raw and clean side 6 . 7 in filter operation of the filter device 8th ,

The support wire 25 prevents deformation or even destruction of the filter medium 23 in a backwashing operation of the filter device 8th , In this case, for example, air at high pressure on the clean side 7 the filter device 8th created, which then to the crude side 6 flows to remove a filter cake formed there when it exceeds a predetermined size.

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

LIST OF REFERENCE NUMBERS

1

Biomass gasification plant

2

carburettor

3

filter

4

CHP

5

filter housing

6

unfiltered side

7

clean side

8th

filter means

9

plate

10

internal combustion engine

11

filter body

12

collar

13

flange

14

The End

15

palm

16

hole

17

The End

18

Tellerboden

19

perforated sheet

20

hole

21

central axis

22

protection fabrics

23

filter media

24

protection fabrics

25

support wire

26

WeldingSpot

D1

diameter

D2

diameter

H

height

Claims (15)

Filter device ( 8th ) for filtering fuel gas produced by gasification of biomass, with a filter body ( 11 ), which is a filter medium ( 23 ), which can be used as tissue ( 23 ), wherein the tissue ( 23 ) is designed as a tank tug. Filtering device according to claim 1, wherein the tissue ( 23 ) has a wire diameter of 20-100 microns. Filtering device according to claim 1 or 2, wherein the tissue ( 23 ) has a wire diameter of 30-100 microns, in particular 30-60 microns. Filtering device according to one of claims 1-3, wherein the fabric is a stainless steel mesh ( 23 ) and / or a nickel-iron alloy. Filter device according to one of claims 1-4, wherein the filter body ( 11 ) within the filter medium ( 23 ) arranged first support material ( 19 ), which is adapted to the filter medium ( 23 ) against a filter operation of the filter device ( 8th ) support for the filtration of the fuel gas generated pressure difference. Filter device according to claim 5, wherein the first support material ( 19 ) is a perforated plate. Filter device according to one of claims 1-6, wherein the filter body ( 11 ) one outside the filter medium ( 23 ) arranged second support material ( 25 ), which is adapted to the filter medium ( 23 ) against in a backwashing operation of the filter device ( 8th ) support the applied pressure difference. Filter device according to claim 7, wherein the second support material ( 25 ) is designed as a support wire. Filter device according to one of claims 5-8, wherein the filter body ( 11 ) a protective material ( 22 . 24 ), which between the first support material ( 19 ) and the filter medium ( 23 ) and / or the filter medium ( 23 ) and the second support material ( 25 ) is arranged. Filter device according to claim 9, wherein the protective material ( 22 . 24 ) Stainless steel and / or a wire diameter greater than 200 microns. Filter device according to one of claims 1-10, wherein the filter body ( 11 ) by means of a collar ( 12 ) on a flange ( 13 ) for attachment of the filter device ( 8th ) on a filter housing ( 5 . 9 ) is attached. Filter device according to one of claims 1-11, wherein the filter body ( 11 ) at one end ( 17 ) is formed closed and / or a plate floor ( 18 ) is provided, which within the filter body ( 11 ) is arranged to reinforce the same. Filter device according to one of claims 5-12, wherein the filter medium ( 23 ) with the first support material ( 19 ), the second support material ( 25 ) and / or the protective material ( 22 . 24 ) is welded. Biomass gasification plant ( 1 ) with a filter device ( 8th ) according to any one of claims 1-13. Use of an armor as a tissue ( 23 ) formed filter medium ( 23 ) of a filter body ( 11 ) a filter device ( 8th ) for filtering fuel gas produced by gasification of biomass.

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