DE102014109397A1 - Rotary grate for a fixed bed gasification reactor - Google Patents

Abstract

The invention relates to a rotary grate for fixed-bed gasification reactors, which has substantially the shape of a stepped cone and the top step is provided with axial gas outlets, so that gasification agent can be introduced in the middle region of the fixed bed on the rotary grate.

Description

Field of the invention

The invention relates to a rotary grate for fixed bed gasification reactor. Likewise, the invention relates to a plant for fixed bed gasification of carbonaceous fuels, is equipped with a fixed bed pressure gasification reactor with a rotary grate according to the invention. Furthermore, the invention relates to a process for the production of synthesis gas wherein the gasification agent is supplied to the fuel via a rotary grate according to the invention.

State of the art

Fixed bed gasification reactors equipped with a rotary grate have been known for a long time. Such a reactor is for example in Ullmann's Encyclopedia of Industrial Chemistry, 6th Edition, Vol. 15, page 369 . 24 described.

On the one hand, the rotary grate has the task of carrying the fixed bed of the fuel and of the ash resulting from the fuel in the reactor. Further, by adjusting the rotational speed of the rotary grate, the amount of ash discharged from the reactor per unit time can be regulated. On the other hand, the rotary grate has the task to introduce the gasification agent, a gas mixture consisting mainly of oxygen, water vapor and, in many cases, nitrogen, as evenly as possible in the fixed bed. The gasification agent is introduced into the reactor below the grate and is introduced into the fixed bed through openings provided in the rotary grate.

The patent DE 968 532 discloses a rotary grate in which the openings are arranged on the surface thereof. The disadvantage of this arrangement, however, is that the openings are directly in contact with the fixed bed lying on the grate or slipping over the grate. There is a risk that particles will penetrate into the openings and block them.

The publication DE 23 51 963 shows a rotary grate, which is composed of interlocking, overlapping cone-shaped parts. Between these parts are the openings for the gas flowing from the grate into the fixed bed gasification agent. Due to the overlapping arrangement of the conical parts, penetration of particles from the fixed bed into the outlet openings of the gasification agent is to be prevented.

However, a disadvantage of this rotary grate is that a large area in the middle of the fixed bed is not reached by the gasification agent, as in the upper part 3a the rotary grate no outlet openings for the gasification agent are present.

The object of the invention is therefore to provide a rotary grate in which the outlet openings of the gasification agent are protected against the ingress of particles from the fixed bed and at the same time is able to enter gasification agent in the central region of the fixed bed.

Description of the invention

The task is solved by a rotary grate 1 for a fixed bed gasification reactor with an inlet 10 for process gas 11 comprising a body 2 substantially having the shape of a stepped cone, each step 3a . 3b . 3c . 3d radial gas outlets 4a . 4b . 4c 4d for process gas and wherein, with the exception of the uppermost stage 3d , each level with a protective shield 5 equipped, which is designed to be the body 2 protects against abrasive contact with the fixed bed and the radial gas outlets 4 shields against the ingress of solid particles from the fixed bed, with a lid 6 to cover the gas outlets 4d the topmost step of the grate 3d , where the lid 6 has substantially the shape of a hollow truncated cone whose base surface is open and larger than the top surface of the uppermost stage 3d is, so that the lateral surface 6a of the lid 6 the top step 3d radially surmounted and thereby their radial gas outlets 4 covering against solid particles and wherein the top surface 6b of the lid 6 the axial gas outlet 7 the highest level 3d gastight covering and where the top surface 6b arranged on a circle gas outlets 6c and wherein these gas outlets of one, a downwardly and radially outwardly open profile having ring 8th be covered against the penetration of solid particles from the fixed bed.

The aforementioned reference numerals are only to illustrate the features of the invention in conjunction with the drawings. They are not intended to be limiting, for example, with respect to the inventive number of items of a claim feature.

Penetration of particles into the radial gas outlets is prevented by covering the outlets with a cone-shaped shield.

The introduction of gasification agent in the central region of the fixed bed is made possible by the cover of the rotary grate is formed as a truncated cone and thus has a horizontal surface which can be equipped with vertically upwardly directed openings. These Openings are placed on a circle for uniform distribution of the gasifying agent in the central region of the packed bed. The penetration of particles into these openings is prevented by the openings are covered by a ring having a downwardly and radially outwardly open profile. This inventive design of the rotary grate lid has been found to be advantageous, since on the one hand allows a good supply of the gasification agent in the center of the fixed bed, on the other hand, but also a good mobility of the rotary grate despite the weight pressure of the load on him fixed bed.

Preferred embodiments of the invention

A preferred embodiment of the invention is that the stepped cone of the body of the grate has at least four stages. With this number of stages, a good compromise is achieved between the stability of the structure against mechanical wear and the uniformity with which the gasification agent is distributed through the rotating grate in the fixed bed.

A further preferred embodiment of the invention is that the open profile of the ring has right-angled edges. Such a profile technically without much technical effort, eg. B. produced as a welded construction.

A further preferred embodiment of the invention is that the open profile of the ring has a substantially semicircular shape. Such a profile can be achieved without great technical effort, eg. B. be prepared by a forging or press molding process.

A further preferred embodiment of the invention is that the bolt circle of the gas outlets is bordered by a serving as a weir tire with a substantially rectangular profile to the gas outlets against the ingress of solid particles or dust, or under the profile on the lid has been saved.

Another preferred embodiment of the invention is a carbonaceous fuel fixed bed gasification plant comprising a fixed bed pressure gasification reactor having a gasification inlet, a product gas outlet, a solid carbonaceous fuel bed arranged on an ash discharge grid, a fuel supply device and an ash removal device, and the ash discharge grid Rotary grate according to claim 1 to 6 is executed. The improved gas distribution through the rotary grate according to the invention leads to a more effective implementation of lying in the middle of the fixed bed part of the fuel.

• a) Bereitstellen einer Anlage zur Festbettvergasung gemäß Anspruch 7,
• b) Zuführen des kohlenstoffhaltigen Brennstoffs über die Brennstoffzuführvorrichtung,
• c) Zuführen eines Sauerstoff und Wasserdampf enthaltenden Vergasungsmittels über den Vergasungsmitteleinlass,
• d) Umsetzen des kohlenstoffhaltigen Brennstoffs unter Vergasungsbedingungen mit dem Vergasungsmittel,
• e) Abführen des Synthesegas-Produktgases über den Produktgasauslass,
• f) Abführen von Asche über den Ascheaustragsrost und die die Ascheabführvorrichtung, wobei das Vergasungsmittel über einen Drehrost gemäß Anspruch 1 bis 6 zugeführt wird.

A further preferred embodiment of the invention consists in a process for the production of synthesis gas containing hydrogen and carbon oxides, comprising the following steps:

• a) providing a fixed-bed gasification plant according to claim 7,
• b) supplying the carbonaceous fuel via the fuel supply device,
• c) supplying a gasification agent containing oxygen and water vapor via the gasification agent inlet,
• d) reacting the carbonaceous fuel under gasification conditions with the gasification agent,
• e) discharging the synthesis gas product gas via the product gas outlet,
• f) discharging ash over the ash discharge grate and the ash removal device, wherein the gasification agent is supplied via a rotary grate according to claim 1 to 6.

embodiment

Other features, advantages and applications of the invention will become apparent from the following description of an embodiment. All of the described features alone or in any combination form the subject matter of the invention, regardless of their combination in the claims or their dependency.

Based on the drawings 1 and 2 the invention will be explained in more detail. Show it

1 a longitudinal section through a rotary grate according to the invention

2 a longitudinal section of the rotary grate according to the invention in the region of the top step and the lid as an enlarged section 1 ,

1 shows the body 2 of the rotary grate 1 as he from the four stages 3a is built up to d. The gasification agent 11 In this example, it is centrally located over the bottom of the body 2 located inlet 10 introduced into the rotary grate. Each of the steps 3a to d is, distributed over the entire circumference, with radial gas outlets 4a equipped to d, through which the gasification agent flows out of the rotary grate. The steps 3a to c are with a protective shield 5a equipped to c. These shields are made of highly durable material and protect the rotating grate from the abrasive action of the ash, which slides down the grate as the lowest part of the fixed bed. In addition, the shields prevent the penetration of particles into the radial gas outlets 4a to c.

1 and particularly 2 show the top step 3d of the rotary grate. This has an axial gas outlet 7 which of a lid 6 is covered gas-tight. The lid 6 is with a lateral surface 6a fitted to the deck area 6b attached and arranged so that they are the radial gas outlets 4d covering against the penetration of particles.

The top surface 6b of the lid 6 is with axial, arranged on a circle gas outlets 6c fitted. About this, the gasification agent is entered in the middle region of the fixed bed. A ring 8th , with a downwards and radially outward open profile, covers the gas outlets 6c against particles from the fixed bed.

The bolt circle of the gas outlets 6c is from a tire acting as a weir 9 is bordered with a substantially rectangular profile to the gas outlets 6c to protect against the penetration of solid particles. Particularly preferred is the upper edge of the tire 9 in the axial direction over the downward and radially outward edge of the ring 8th arranged. In this way, a particularly efficient removal of particles from the fixed bed is possible.

Industrial Applicability

The rotary grate according to the invention enables safe entry of gasification agent into the middle region of the fixed bed of a fixed-bed gasification reactor and is thus able to increase the performance and cost-effectiveness of a fixed-bed gasification reactor.

LIST OF REFERENCE NUMBERS

1

rotary grate

2

Body of the rotary grate 1

3a, b, c, d

radial gas outlets

4a, b, c, d

Steps in the outer profile of the rotary grate 1

5a, b, c

shields

6

cover

6a

Lateral surface of the lid 6

6b

Top surface of the lid 6

6c

axial gas outlets of the lid 6

7

axial gas outlet of the stage 3d

8th

Ring for covering the gas outlets 6c

9

Tire to cover the gas outlets 6c

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 968532 [0004]
• DE 2351963 A [0005]

Cited non-patent literature

• Ullmann's Encyclopedia of Industrial Chemistry, 6th Edition, Vol. 15, page 369 [0002]

Claims (7)

rotary grate 1 for a fixed bed gasification reactor with an inlet 10 for process gas 11 comprising a body 2 substantially having the shape of a stepped cone, each step 3a . 3b . 3c . 3d radial gas outlets 4a . 4b . 4c 4d for process gas and wherein, with the exception of the uppermost stage 3d , each level with a protective shield 5 equipped, which is designed to be the body 2 protects against abrasive contact with the fixed bed and the radial gas outlets 4 shields against the ingress of solid particles from the fixed bed, with a lid 6 to cover the gas outlets 4d the topmost step of the grate 3d , where the lid 6 has substantially the shape of a hollow truncated cone whose base surface is open and larger than the top surface of the uppermost stage 3d is, so that the lateral surface 6a of the lid 6 the top step 3d radially surmounted and thereby their radial gas outlets 4 covering against solid particles and wherein the top surface 6b of the lid 6 the axial gas outlet 7 the highest level 3d gastight covering and where the top surface 6b arranged on a circle gas outlets 6c and wherein these gas outlets of one, a downwardly and radially outwardly open profile having ring 8th be covered against the penetration of solid particles from the fixed bed. Rotary grate according to claim 1, characterized in that the stepped cone of the body 2 at least four levels 3a to d. Rotary grate according to one of claims 1 and 2, characterized in that the open profile of the ring 8th has right-angled edges. Rotary grate according to one of the preceding claims, characterized in that the open profile of the ring 8th has a substantially semicircular shape. Rotary grate according to one of the preceding claims, characterized in that the bolt circle of the gas outlets 6c from a tire acting as a weir 9 is bordered with a substantially rectangular profile to the gas outlets 6c to protect against the penetration of solid particles. A fixed bed gasification plant for carbonaceous fuels comprising a fixed bed pressure gasification reactor having a gasification inlet, a product gas outlet, a solid carbonaceous fuel bed arranged on an ash discharge grid, a fuel supply device, an ash removal device, characterized in that the ash discharge grid is constructed as a rotary grate according to claims 1-5. A process for producing synthesis gas containing hydrogen and carbon oxides comprising the steps of: a) providing a fixed bed gasification plant according to claim 6, b) supplying the carbonaceous fuel via the fuel supply device, c) supplying a gasification agent containing oxygen and water vapor via the gasification inlet, d E) discharging the syngas product gas via the product gas outlet, f) discharging ash via the ash discharge grate and the ash removal device, characterized in that the gasification agent is supplied via a rotary grate according to claims 1-5 becomes.

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