EP0807788B1 - Grate arrangement for incineration of domestic refuse - Google Patents

Abstract

An incinerator grille consists of a series of alternating and overlapping fixed (9) and moving bars with holes (10A) for an air flow from a blower chamber beneath the grille. The grille is bounded at the sides by at least one vertical edge plate (11) which has one or more recesses (11A) for the edge of a bar. The grille can have two edge plates, each with a series of recesses for the bar edges. Each recess extends from the lower edge (11B) of the plate and has an upper edge (11C) corresponding to the shape of a fixed bar.

Description

The present invention relates to a grid incineration of household waste.

It relates more precisely to a grid household waste incineration consisting of a row fixed bars and mobile bars translated on these last, these fixed and mobile bars being interposed and provided with supply air passage openings a blowing chamber disposed under the grid, said row being bounded laterally by two plates of substantially vertical bank.

There is such a grid in an installation household waste incineration where the waste is introduced via a hopper into a well, are pushed to the bottom of this well by a drawer towards the inclined grid where is performed the combustion of waste as well as its transfer at the end of the grid where they are discharged into a bin cooling.

A grid of this type is described in the document of Patent FR-2,574,160.

In such a grid, the bars are currently juxtaposed with minimal clearance against the edge plate. This minimum clearance must allow differential expansion of bars and the edge plate and the translation of movable bars. Now through this game, blowing air passes blown into the blowing chamber located under the grid and which escapes vertically along the plate shore.

By its flow, this air contributes very little to the combustion of waste and constitutes an air leak not negligible since, in the case of a limited grid laterally by two edge plates, approximately 50% of the air blowing is lost.

The present invention proposes to solve this problem and it relates to a household waste incineration grid as defined above, characterized in that each edge slap is provided with a series of hollows each receiving a fixed bar.

This arrangement has three advantages.

It is thus obtained a passage in air baffle in said game which decreases its speed. It is so possible to effectively regulate the air flow from blowing and reduce nitrogen oxide emissions.

At the end of the chicane passage, the air flows into a substantially horizontal direction and therefore penetrates the mass of waste, thus effectively participating in their combustion.

The chicane-shaped game is opposed to the passage to through the grid of fine particles or small metal parts from the mass of waste. At on the contrary, the particles tend to accumulate at the horizontal mouth of the chicane passage and at the plug, further limiting air leakage.

For reasons of ease of manufacture and for avoid difficulties in guiding tolerance, this arrangement only concerns the bars fixed which, by the classical constitution of such grid, correspond to approximately 85% of the length of the games lateral.

Preferably, each hollow has the shape of a rebate vertical plane bottom, extending to the lower edge of the edge plate and whose upper edge has substantially the profile of the corresponding fixed bar.

In this way, the bar is fitted into the rebate with minimum vertical clearance from the bottom of the latter and a minimum horizontal clearance with respect to the edge superior of it.

The invention is described below in more detail at using figures representing only one embodiment preferred of the invention.

Figure 1 is a partial view in vertical section a household waste incineration facility.

Figure 2 is a partial sectional view longitudinal of an incineration grid.

Figure 3 is a front view of an edge plate forming part of such an incineration grid in accordance with the invention.

Figure 4 is a partial sectional view transverse of a fixed bar of such a grid conforming to the invention.

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

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

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

The bars of the grid 4 are alternately fixed or mobile, as will be seen more precisely below, and gradually move the mass of waste burned towards a evacuation well 6 where the waste falls into a bin cooling 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 onto the latter, these fixed and mobile bars being interposed and provided with openings 9A, 10A for blowing air passage.

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

The row of bars is laterally limited by a vertical edge plate 11 made up of several panels juxtaposed and united. Typically, the grid has such an edge plate 11 on each of its edges lateral.

As shown in Figure 3, the edge plate 11 is provided with a series of recesses 11A in which is fitted the side edge of each fixed bar 9. More precisely, each hollow 11A has the shape of a rebate of vertical flat bottom, extending to the bottom edge 11B of the plate 11 and whose upper edge 11C has substantially the profile of the corresponding fixed bar 9.

Each fixed bar 9 is fitted into a rebate 11A as shown in figure 4. Between the edge plate 11 supported by a support structure 12 and the fixed bar 9 is made a minimum clearance taking into account the expansions differentials.

This game constitutes a flight from chicane to the supply air under the bars 9, 10 in the blowing chamber 5. This passage in baffle causes a decrease in the leak rate, a flow substantially horizontal air at the exit of the passage and therefore a air penetration into the waste mass and its contribution to the combustion of it and finally opposes the fall of fine solid particles which tend to contrary to the butcher.

Claims (2)

1. Grate for incineration of domestic waste comprising a row of fixed bars (9) and mobile bars (10) moving in translation on the latter, said fixed and mobile bars being interleaved and provided with orifices (9A, 10A) through which passes blowing air from a blowing chamber (5) disposed under the grate, said row being delimited laterally by two substantially vertical side plates (11), characterized in that each side plate is provided with a series of recesses (11A) each receiving a fixed bar (9).
2. Grate according to claim 1, characterized in that each recess (11A) is in the form of a rebate with a vertical flat bottom extending to the bottom edge (11B) of the plate and the top edge (11C) of which has substantially the same profile as the corresponding fixed bar (9).

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