FR2758383A1 - Incinerator grill for waste - Google Patents

Abstract

The incineration grill has a row of bars (9) extending transversely of the longitudinal axis of the row and having openings (9A,10) for passage of blown air to a chamber (5) under the grill. The grill can have a plate (11) extending vertically at each side edge. Each bar has at least two sections (910) which are fixed in opposing positions across the longitudinal axis of the grill. An expansion compensator insert is placed between the sections. The insert can be formed by a spring tension bar (27).

Description

 HOUSEHOLD INCINERATION GRID.

 The present invention relates to a household waste incineration grid.

 More precisely, it relates to a household waste incineration grid consisting of a row of bars arranged transversely to the longitudinal axis of the row and provided with orifices for the passage of blowing air coming from a blowing chamber disposed under the grid, said row being limited on each side by a substantially vertical edge plate and each bar consisting of at least two integral modules juxtaposed transversely to the longitudinal axis of the row.

 There is such a grid in a household waste incineration installation where the waste is introduced via a hopper into a well, is pushed to the bottom of this well by a drawer towards the inclined grid and where the combustion of waste is carried out. as well as their transfer to the end of the grid where they are discharged into a cooling tank. The grid is generally made up of alternately fixed and mobile bars and each bar is made up of a certain number of identical modules assembled rigidly, often by bolting.

 In such a grid, the bars are currently juxtaposed with minimal clearance to the edge plates. This minimum clearance must allow the differential expansion of the bars and the edge plates. However, through this play, blown air blown into the blowing chamber disposed under the grid and which escapes vertically along the edge plate.

 Given its flow, this air contributes very little to the combustion of waste and constitutes a significant air leak since about 50k of the blowing air is thus lost.

 The invention solves this problem by allowing the clearance existing between the bars and the edge plates to be eliminated, and in order to do this, in accordance with the invention, an expansion compensating arrangement is arranged between said modules.

 It is thus possible to effectively regulate the flow rate of the supply air and to reduce the emissions of nitrogen oxides.

 We eliminate the passage through this game through the grid of fine particles or small metal parts from the mass of waste.

 According to a first embodiment, the expansion compensating arrangement comprises two sections of bars, called elements, connected to each other by a device allowing the sections to be moved towards one another and having contiguous edges allowing this movement over a stroke corresponding to maximum expansion and is secured in a known manner to said modules.

 This first solution has the advantage of being able to be installed without modifying the existing bar modules, said compensating arrangement being simply interposed between two modules and assembled to them in a known manner, for example by bolting.

 According to a second embodiment, the expansion compensating arrangement comprises a device connecting said modules, said elements, and allowing the displacement of said modules towards each other, said modules comprising contiguous edges allowing this displacement over a corresponding stroke at maximum dilation.

 According to this second solution, the modules must be designed and machined in a particular way to receive said device and present said contiguous edges.

 Advantageously, said device comprises at least one tie connecting two flanges integral with the elements and urged by a compression spring.

 This device is particularly simple to make and suitable for the operating conditions of an incineration grid.

 According to a particular embodiment, said contiguous edges have a play of blowing air passage.

 This air passage completes the blowing of air through the grate and combustion.

 The invention is described below in more detail using figures showing only a preferred embodiment of the invention.

 Figure 1 is a partial vertical sectional view of a household waste incineration plant.

 FIG. 2 is a partial view in longitudinal section of an incineration grid.

 Figure 3 is a partial longitudinal sectional view of a bar of an incineration grid, according to the first embodiment of the invention.

 Figure 4 is a partial longitudinal sectional view of a bar of the same grid, according to a variant.

 Figure 5 is a sectional view along V-V of Figure 3.

 Figure 6 is a partial longitudinal sectional view of a bar of an incineration grid, according to the second embodiment of the invention.

 Figure 1 is intended to locate an incineration grid, object of the invention, in a waste incineration installation.

 The waste is poured into a hopper 1 and falls into a well 2 at the bottom of which it is received on a horizontal surface and pushed by a pusher 3 onto the inclined incineration grid 4.

 Under this grid 4 formed of transverse bars provided with orifices, there is a blowing chamber 5 into which is blown combustion air which passing through said orifices burns the mass of waste being on the grid 4. Above from the grid 4, the fumes are evacuated in a duct 8 to a device for treating the fumes.

 The bars of the grid 4 arranged transversely to the longitudinal axis of the row are alternately fixed or mobile, as will be seen more precisely below, and gradually move the mass of burnt waste towards an evacuation well 6 where the waste falls in a cooling tank 7 and are recovered.

 In Figure 2 is shown in more detail the incineration grid 4. It consists of a row of fixed bars 9 and mobile bars 10 translated on the latter, these fixed and mobile bars being interposed and provided with holes 9A , 10A for supply air passage.

 The support arrangement 13 of the fixed bars 9 and that of translational drive 14 of the mobile bars 10 are shown diagrammatically in the figure and generally consist of fixed vertical supports for the first and mobile beams for the second .

 The row of bars is limited on each side by a vertical edge plate 11.

 Conventionally, each bar 9, 10 consists of at least two modules 9 ', 9 "or 10', 10" integral juxtaposed transversely to the longitudinal axis of the row.

 A first embodiment of the invention is shown in Figures 3 to 5.

 As can be seen in FIG. 3, two modules 9 ′, 9 "or 10 ′, 10" are partially visible there and a expansion compensating arrangement 20 is arranged between them. This expansion compensating arrangement 20 comprises two sections of bars 21, 22 connected to each other by a device 27 allowing the sections 21, 22 to move towards each other and having contiguous edges 23, 24 allowing this displacement over a stroke d corresponding to maximum expansion. The section 21 is secured in a known manner to the module 9 'or 10' for example by bolting 25 of flanges and, in the same way, the section 22 is secured to the module 9 "or 10" for example by bolting 26 of flanges.

 The device 27 consists of several identical arrangements, as it can be seen in FIG. 5, each comprising a tie rod 28 connecting two flanges 29, 30 integral with one of the section 21 and the other of the section 22.

To do this, it passes through orifices facing each other made in these flanges 29, 30 and comprises at each of its ends a locking ring. It is biased by a compression spring 31 disposed around it between the two flanges 29, 30. This spring 31 therefore tends to push the two sections 21, 22 distant from each other.

 The contiguous edges 23, 24 are conventionally shaped to an expansion joint, that is to say an overlap.

 According to a variant shown in FIG. 4, they have a clearance j for the passage of blowing air.

 As visible in FIG. 5, the section 22 or 21 has the same profile as the bar modules with which it is associated, here a known form of bar is shown. The device 27 may include four arrangements as previously described, of which the tie rods 28 are visible.

Also visible in this figure are the orifices 26A intended to receive the bolts for fixing the section 22 to the adjacent module 9 ", 10".

 According to the second embodiment of the invention shown in Figure 6, the two bar modules 9 ', 9 "or 10', 10" are directly secured using the expansion compensating arrangement comprising a device 27 the connecting and allowing their displacement towards each other, the modules 9 ', 9 "or 10', 10" having contiguous edges 32, 33 allowing this displacement over a stroke d corresponding to maximum expansion.

 Except for this direct connection without sections of bars interposed, this compensating arrangement is identical to that previously described.

 Thanks to the invention, any play between the bars and the edge plates can be eliminated, the compensating arrangement according to the invention allowing the displacements relative to the differential expansion while ensuring the maintenance without play of the bars against the edge plates .

 The compensator arrangement can be adapted to any type of profile of the bars.

Claims (5)

 1) Household waste incineration grid consisting of a row of bars (9, 10) arranged transversely to the longitudinal axis of the row and provided with orifices (9A, 10A) for passage of supply air coming from '' a blowing chamber (5) disposed under the grid, said row being limited on each side by a substantially vertical edge plate (11) and each bar (9, 10) consisting of at least two modules (9t, 9 ", 10 ', 10") integral juxtaposed transversely to the longitudinal axis of the row, characterized in that a expansion compensating arrangement is disposed between said modules (9', 9 "or 10 ', 10").  2) Grid according to claim 1, characterized in that the expansion compensating arrangement comprises two sections of bars (21, 22), said elements, connected to each other by a device (27) allowing the movement of sections (21, 22) towards each other and having contiguous edges (23, 24) allowing this movement over a stroke (d) corresponding to maximum expansion and is secured in a known manner to said modules (9 ', 9 "or 10 ', 10")  3) Grid according to claim 1, characterized in that the expansion compensating arrangement comprises a device (27) connecting said modules (9 ', 9 "or 10', 10"), said elements, and allowing the displacement of said modules (9 ', 9 "or 10', 10") towards each other, said modules (9 ', 9 "or 10', 10") having contiguous edges (32, 33) allowing this movement over a stroke (d) corresponding to maximum expansion.  4) Grid according to claim 2 or 3, characterized in that said device (27) comprises at least one tie rod (28) connecting two flanges (29, 30) integral with the elements and urged by a compression spring (31).  5) Grid according to claim 2 or 3, characterized in that said contiguous edges (23, 24, 32, 33) have a clearance of blowing air passage.