FR3065277A1 - DECISION GRID - Google Patents

Abstract

The invention relates to a deashing grid (1) comprising rotating bars (2) held by a support (3), characterized in that a mouth (4) intended to receive at least one intake duct (5). ) of fuel is arranged through the grid. In a first embodiment, the bars are oriented in concurrent directions. In a second embodiment, the bars are oriented parallel to each other. The bars may be finned to crush the slag, and bored to let a gas. The grid according to the invention is suitable for different combustion plants such as boilers and gasifiers.

Description

065 277

53181 ® FRENCH REPUBLIC

NATIONAL INSTITUTE OF INDUSTRIAL PROPERTY © Publication number:

(only to be used for reproduction orders) © National registration number

COURBEVOIE © Int Cl ⁸ : F23 H 9/08 (2017.01)

PATENT INVENTION APPLICATION

A1

©) Date of filing: 12.04.17. © Applicant (s): MINI GREEN POWER— FR. (© Priority: @ Inventor (s): RIONDEL JEAN, LAFLEUR JEAN, BILLAUD JOSEPH and CHAPUIS ARNAUD. (43 / Date of public availability of the request: 19.10.18 Bulletin 18/42. ©) List of documents cited in the report preliminary research: Refer to end of present booklet (© References to other national documents ® Holder (s): MINI GREEN POWER. related: ©) Extension request (s): © Agent (s): CABINET HAUTIER.

pA) ASH GRID.

FR 3 065 277 - A1 _ The invention relates to an ashtray grate (1) comprising rotary bars (2) held by a support (3), characterized in that a mouth (4) intended to receive at least a fuel intake duct (5) is arranged through the grid. In a first embodiment, the bars are oriented in concurrent directions. In a second embodiment, the bars are oriented parallel to each other. The bars can be provided with fins so as to crush the clinkers, and bored in order to let pass a gas. The grate according to the invention is suitable for different combustion plants such as boilers and gasifiers.

i

FIELD OF THE INVENTION

This invention relates to the field of energy, and more specifically installations operating on the basis of combustion, gasification, or any other thermochemical process involving solid fuels.

The present invention relates more precisely to an ash removal module intended to equip a boiler or gasifier hearth making it possible to burn all types of solid combustible or semi-combustible materials.

TECHNOLOGICAL BACKGROUND

The materials to be burned, in particular solid recovery fuel (CSR) and agricultural biomass, produce during their combustion ash and bottom ash and possibly contain non-combustible foreign bodies (metal residues, glass). Clinkers are solid residues of combustion and can form when the melting temperature of the ashes of a given biomass is exceeded. All of these combustion residues must be regularly evacuated in order to maintain efficient combustion in the fireplace. This operation is called ash removal.

An ash removal device usually includes a grate located under the combustion hearth. This grid can be made up of rotary bars with an integrated air blower, if necessary, to supply the combustion chamber with combustion. Such a grid is disclosed in document WO 93/11389 A1. A set of rotary bars linked to each other by links is placed on running rails. The bars are rotated by moving the assembly on the running rails and allowing the ash from the hearth to be removed. The bars can be hollow and pierced for the injection of oxidant.

Another rotary bar grid device is disclosed in the document US

5027719. The bars of this system are driven in pairs via gears. Each pair of bars is independent and has its own drive mechanism. The bars can be provided with reliefs and projections.

Document US 433519 discloses a grid consisting of bars which are alternately fixed and mobile. The movable bars are driven by a crank and a set of gears. They can be threaded or provided with spikes, fins, or any other shape. This document dates from 1890 and attests to a long tradition of grids with rotary bars.

Other ash removal devices such as scrapers on a rotating bottom, or with jacks, oscillating or vibrating movable grids, or even rotating bottom plates are also known.

The use of rotary bars provided with reliefs advantageously makes it possible to break the bottom ash and solid combustion residues.

Another essential element in the operation of a combustion system is the fuel intake duct. This element increases the size of the combustion system. The intake duct can be positioned above the fireplace, on one side of the fireplace or below the combustion fireplace. This last configuration allows more precise control of the flow of combustible materials feeding the combustion furnace.

The present invention takes up the advantage provided by a grid design with rotary bars for crushing bottom ash, by providing a solution to the problem of space requirement linked to the grid and intake duct elements. The present invention also optionally provides an optimal configuration for the supply of solid fuel.

Another potential advantage of the present invention is its modularity and its compatibility with different combustion plants.

SUMMARY OF THE INVENTION

A first aspect of the invention relates to an ash removal grid intended to receive a combustion hearth. This grid comprises bars and a support for bars, arranged in such a way that the bars are kept free to rotate on their longitudinal axis.

Advantageously, at least one mouth allowing to receive at least one fuel intake duct is arranged through the grid, so that at least one bar borders said at least one mouth.

This arrangement overcomes the problem of space by allowing the integration of the intake duct directly within the grid. Surprisingly, this compact solution ensures both optimized fuel intake directly under the grid, and is capable of crushing clinkers. It was not considered because it seemed hitherto incompatible to provide rotary bars and a mouth of the intake duct at the same level of the installation; in fact, the bars are bulky elements and imply a power transmission for their rotation so that they are currently perceived as a coherent, autonomous entity, which cannot be coupled with another body. The invention combats this prejudice.

Another separable aspect of the invention is a grid in which the longitudinal axes of the bars are oriented in concurrent directions. This offers new possibilities for providing fuel supply and / or ash disposal spaces.

According to one possibility, the bars can be fitted with fins or other projections so as to break the bottom clinkers and simultaneously entrain solid residues.

Another possibility includes hollow or pierced bars, and fins possibly pierced so as to pass a gas. This gas can thus be injected into the reactor while serving to cool the bars and the fins.

The invention also relates to a combustion or gasification plant comprising such a grid.

A separable aspect of the invention relates to an ash grate intended to receive a combustion hearth. This grid comprises bars and a support for bars, arranged so that the bars are kept free to rotate on their longitudinal axis, the longitudinal axes of the bars being oriented in concurrent directions. The directions are optionally concurrent at a central point of the grid, and fuel can be admitted from above or from below or even laterally to the grid.

BRIEF INTRODUCTION OF FIGURES

Other characteristics, objects and advantages of the present invention will appear on reading the detailed description which follows, and with reference to the appended drawings given by way of nonlimiting examples and in which:

- Figure 1 shows a first embodiment of a grid according to the invention;

- Figure 2 shows a second embodiment of a grid according to the invention;

- Figure 3 shows a sectional view of a grid according to the invention installed in a boiler.

DETAILED DESCRIPTION

Before entering into the detail of preferred embodiments of the invention with reference in particular to the drawings, other optional features of the invention, which can be implemented in a combination in any combination or in an alternative, are indicated below:

- at least two distinct portions of the periphery of the at least one mouth are each bordered by at least one bar.

- The longitudinal axes of the bars are oriented in concurrent directions. The directions are optionally concurrent at a central point on the grid.

- The longitudinal axes of the bars are oriented in parallel directions.

- at least a portion of the periphery of the mouth corresponds to at least a portion of the support, the remaining portions of the periphery of the mouth being bordered by bars.

- the mouth extends from the center of the grid.

- The bars include at least one element among a fin, a thread, a tooth, a projection and a recess over at least part of their length. Such an element of a first bar is configured to cooperate with at least one element of at least one adjacent bar by a rotation setting. Optionally, at least two fins are connected together by at least one inclined panel.

- at least one bar comprises at least one element from a longitudinal bore and a transverse bore, configured so as to allow the passage of a gas.

- The bars are rotated by actuation on the periphery of the grid.

Generally, in the invention, the bars have a function of reducing, by grinding or crushing, combustion residues. They are rotatable and sufficiently adjacent to each other to define spaces of reduced size for mechanical stressing of the materials to be treated, in particular clinkers to be ground. Advantageously, the bars each comprise a body provided with projecting members, the adjacent bar members being nested or interdigitated.

Unless otherwise stated or there is an incompatibility, the characteristics of one of the embodiments of the invention may be applied to another embodiment.

Referring to Figure 1, a first embodiment of the grid 1 according to the invention includes bars 2 arranged radially, held by a support 3 over one or more portions of their length. For example, a cylindrical guide 31 possibly provided with internal bearings, supported by a square 32, covers a portion of a bar. The length of this portion can reach half the length of a bar. The length of a bar is between 10 cm and 80 cm. The outside diameter of the support 3 is between 60 cm and 2 m. The support 3 is for example a crown in the form of a cylinder section and / or may comprise a fixing frame 33 bored and dedicated to the connection to a boiler body for example. The longitudinal axes of the bars are preferably in the same plane. An additional part, preferably at a mouth 4 discussed below can also guide the bars in rotation, in addition to the support 3.

A mouth 4, preferably cylindrical, is advantageously provided in the center of the grid 1. This mouth 4 is intended to receive an intake duct 5. The diameter of the mouth 4 is between 10 cm and 30 cm. The periphery of the mouth 4 is entirely bordered by eight bars for example; it can be centered on a point of concours of the axes of the bars and / or the center of the grid.

Each bar may include in particular a part provided with fins 10, 11 interconnected by sides 12 which are advantageously inclined. Preferably, these fins are directed along a main plane defined by the longitudinal axis of the bar and a direction radial to this axis. They can be four in number and / or be regularly distributed around the bar body. These fins are for example of trapezoidal shape, advantageously with a decreasing section in the direction of one end of the bar located towards the center of the grid, so as to ensure good cooperation with the fins of the adjacent bars during the synchronized rotation of the bars. . This design makes it possible in particular to ensure good overlap between the fins by a rotation setting (an adjustment of the angular offset between the fins of two adjacent bars). The fuel of the hearth is thus advantageously maintained on an upper face of the grate during combustion, while the bottom ash or the combustion residues are effectively crushed on a lower part of the grate.

The inclined faces 12 have angles of inclination between 0 ° and 30 ° relative to the direction of the longitudinal axis and serve both as mechanical reinforcements to the fins, and as elements making it possible to orient the sliding of the solid fuel. towards the center so as to concentrate the fuel. This latter effect increases the combustion efficiency of the fireplace. According to one possibility, the flaps 12 are not in contact with the body of the bars so as to prevent the fuel from jamming at the foot of the fins.

The bars preferably have in their body a longitudinal bore 13 allowing gas to be introduced by blowing. This gas can be both a cooling gas and the oxidant supplying the combustion furnace. The bars can preferably be drilled radially for this purpose.

The fins can also be drilled so as to let a gas pass through a gasifier for example.

Bars, fins and inclined faces may be made of steel.

The rotation of a bar can be carried out by means of a peripheral actuation 14. This actuation 14 comprises in the illustrated case a toothed wheel 141, a bevel gear 142 and a gear 143. Each bar has its own actuation 14. All the actuations are advantageously connected together by a chain 144, so that the actuation of one leads to the action of the others.

Advantageously, a single motor connected to at least one actuation 14 is sufficient to cause the rotation of all the bars of the grid 1 synchronously. In order to transmit significant torque to the bars, and to keep the solid fuel long enough for it to burn, the bars have a slow rotation speed, between 0.05 rpm and 0.2 rpm.

A second embodiment of the grid 1 according to the invention includes, with reference to FIG. 2, bars 2 arranged parallel to each other, held by a support 3 over one or more portions of their length. The bars have different lengths so as to cover part of the surface delimited by the support 3. The bars pass through the support 3 from one side so that one end of each bar joins an actuation external to the support 3. The support 3 may include a fixing frame 33 bored and dedicated to the connection to a boiler body for example. The longitudinal axes of the bars are in the same plane.

A rectangular mouth 4 is advantageously provided through the grid 1 so as to receive an intake duct 5. Separate portions 6, 7 of the periphery of the mouth 4 are each bordered by at least one bar. It is noted that the two portions 6, located opposite one another around the mouth 4, are each adjacent to a bar and are parallel to the bars; another portion 7, transverse to the previous ones, is perpendicular to the axes of the bars; a wall on this portion can be used for guiding in rotation one or more bars bordering the mouth 4 at this location. A last portion 8 of the periphery of the mouth 4 corresponds here but not limited to a portion 9 of the support 3. However, it is possible that the entire periphery of the mouth 4 is surrounded by bars, the portion 8 being bordered by bars, like the portion 7. The mouth 4 preferably has a rectangular or square section, one of the sides of this section being advantageously parallel to the direction of the axes of the bars.

The length of the mouth 4 is for example between 20 cm and 80 cm. The width of the mouth 4 is for example between 10 cm and 30 cm. At the location of the mouth 4, the bars can have a shorter length so as to accommodate the size of the mouth 4. If the grid is circular, there are thus bars of increasing length from a rope at the periphery of the grid, then of bars of shorter lengths at the level of the mouth 4, then of bars of decreasing lengths to a cord on the periphery of the grid, opposite to the first cord.

Each bar comprises in particular a part provided with fins 10, 11. These fins are of rectangular shape so as to ensure good cooperation with the fins of the adjacent bars during the synchronized rotation of the bars. The length of the fins is for example between 5 cm and 1.5 m. The width of the fins is for example between 1 cm and 10 cm. For example, certain bars illustrated in FIG. 2 include wider fins so as to compensate for a greater spacing between their longitudinal axes. Cooperation by overlap between fins of adjacent bars is thus preserved. The fins can be pierced so as to allow gas to pass through.

Similarly to the first embodiment, the bars preferably have a longitudinal bore 13 and can also be drilled.

The rotation of a bar is carried out by means of an actuation external to the support 3. This actuation is not shown in the figures insofar as the skilled person knows such actuation including gears by the state of technique.

Another embodiment illustrated in FIG. 3 also includes a combustion plant 15 equipped with a grate 1 according to the invention.

The invention is not limited to the embodiments described above but extends to all embodiments in accordance with its spirit.

According to a variant of the embodiments previously described, the longitudinal axes of the bars are not contained in the same plane.

A radial arrangement of these can then generate a conical or frustoconical grid shape.

A parallel orientation of these can result in a staggered or staggered arrangement of the bars.

REFERENCES

1. Ash removal grid

2. Bars

3. Bars support

31. Guide

32. Square

33. Fixing frame

4. Mouthpiece

5. Intake duct

6, 7, 8. Separate portions of the mouthpiece

9. Portion of the support

10. Fins

11. Fins

12. Inclined panels

13. Longitudinal bore

14. Activation

141. Gear wheel

142. Bevel gear

143. Gear

144. Chain

15. Combustion plant ίο

Claims (13)

1. Ash removal grid (1) comprising at least two bars (2) and a support (3) for bars, the bars (2) being configured to be rotated on their longitudinal axis relative to the support (3), characterized in what the grid (1) includes: at least one mouth (4) intended to receive at least one fuel intake duct (5) and arranged through the grid (1), so that at least one bar borders said at least one mouth (4) . 2. Ash grate according to claim 1, in which at least two portions (6, 7) distinct from the periphery of said at least one mouth (4) are each bordered by at least one bar (2). 3. Ash grate (1) according to any one of the preceding claims, in which the longitudinal axes of the bars (2) are oriented in concurrent directions. 4. Ash removal grid (1) according to the preceding claim, in which the directions are concurrent at a central point of the grid (1). 5. Ash removal grid (1) according to any one of claims 1 to 2, wherein the longitudinal axes of the bars (2) are oriented in parallel directions. 6. Ash grate (1) according to any one of the preceding claims, in which at least a portion (8) of the periphery of the mouth (4) corresponds to at least a portion (9) of the support, the portions remaining from the periphery of the mouth (4) being bordered by bars (2). 7. Ash removal grid (1) according to any one of the preceding claims, in which the mouth (4) extends from the center of the grid. 8. Ash grate (1) according to any one of the preceding claims, in which the bars comprise at least one element from a fin (10), a thread, a tooth, a projection and a recess on at least part of their length. 9. Ash grate (1) according to the preceding claim, wherein at least two fins (10, 11) are interconnected by at least one inclined face (12). 10. Ash grate (1) according to claim 8, wherein an element of a first bar is configured to cooperate with at least one element of at least one adjacent bar by a rotation setting. 11. Ash removal grid (1) according to any one of the claims 5 above, in which at least one bar (2) comprises at least one element from a longitudinal bore (13) and a transverse bore, configured so as to allow the passage of a gas. 12. Ash grate (1) according to any one of the preceding claims, in which the rotation of the bars is carried out by a 10 actuation (14) on the periphery of the grid (1). 13. Combustion plant (15) comprising a grate (1) according to any one of the preceding claims. 1/3 2/3 FSG. 2 3/3 HG. 3