FR2531519A1 - Cooled and deep fluidised bed with an exchanger with removable tubes - Google Patents

Abstract

Fluidised bed characterised in that the vertical collectors 1, to which the tubes 2 constituting the horizontal layers are connected, are arranged within the combustion chamber 3, and are equipped with special narrow flanges 4, and in that the screen 8 of tubes with vertical fins 6 embedded in refractory concrete 7 has, in the region of the outlet of the horizontal tubes 2, a gap 5 between the tubes of the screen 8 allowing the passage of the flanges 4 of the vertical collectors 1, which are connected, at their upper portion, by the intermediary of a flanged elbow 9 to the screen 8.

Description

 The present invention relates to the field of industrial hearths with a fluidity bed, and has for its object a fluidity bed equipped with an exchanger with removable tubes.

 Currently, fluidized beds can be cooled by means of inclined and crossed tubes, immersed in fluidized materials, and in which water thermosiphon circulates.

 The known tubes of existing fluidized beds are connected by welding to collectors in the workshop or during assembly and are tested during tests to verify the welds. In normal operation, the tubes immersed in the bed are subjected to brushing. materials and are eroded, so their replacement is necessary with a periodicity of several years.

 However, such a replacement requires a long and painful intervention because the worn tubes must be assembled by mechanical cutting or by oxygen cutting and that the reassembly and assembly of the new tubes are carried out by welding.

 In addition, after such assembly by welding, the pressure parts received must undergo a complete regulatory retest penalizing maintenance costs for the operator.

The object of the present invention is to overcome these drawbacks
It has, in fact, for its object a fluidized bed connected to an industrial boiler characterized in that the vertical collectors, to which the tubes constituting the horizontal layers are connected, are arranged outside the combustion chamber, and are provided with narrow flanges, and in that the screen of vertical tubes has, at the outlet of the horizontal tubes, an interval between tubes of the screen allowing the passage of the flanges of the vertical collectors, which are connected, at their upper part , via a flange elbow, on the screen.

 The invention will be better understood from the description below, which relates to a preferred embodiment, given by way of nonlimiting example, and explained with reference to the accompanying drawings, in which FIG. 1 is a partial view in cross section showing a tube assembly according to the invention Figure 2 is a partial sectional view along AA of Figure 1, and Figure 3 is a front elevational view showing the connection of a vertical manifold.

 According to the invention, and as shown more particularly, by way of example, Figures 1 and 2 of the accompanying drawings, the fluidized bed has vertical collectors 1 on which the tubes 2 are welded, which constitute the horizontal sheets , and are arranged outside the combustion chamber 3. These vertical collectors 1 are provided at their ends with special narrow flanges 4 facilitating their passage in an interval 5 between the vertical fin tubes 6 of the screen 8 for the 'insertion and removal of the vertical bundles of tubes 2. These vertical tubes 6 are embedded in a refractory concrete 7 (Figure 2).

 At their upper part, the vertical collectors 1 are connected to the screen 8 by means of a flange elbow 9, which facilitates the correct disassembly and reassembly of said collectors 1.

 The openings for the passage of the tubes 2 are obstructed by means of refractory concrete 7 (FIG. 2), and the tightness of the combustion chamber 3 is completed by an external lining 10 in fixed form on the screen 8 by means of spacers 11 integral with the fins of the vertical tubes 6 of the screen 8.

 Thanks to the invention, it is possible to easily replace the tubes of a fluidized bed of an industrial boiler by simple dismantling of the manifolds 1 at the flanges 4 and removal through the gap 5 between the tubes 6, then by reassembly in the opposite direction of a new manifold assembly 1 and tubes 2 and pouring of a refractory concrete 7, and installation of the outer liner 10, without requiring any de-welding operation of the parts under pressure.

 Thus, a tube replacement can be carried out quickly and easily and without requiring a complete regulatory test.

 Of course, the invention is not limited to the embodiment described and shown in the accompanying drawings.

Modifications remain possible, in particular from the point of view of the constitution of the various elements, or by substitution of technical equivalents, without thereby departing from the scope of protection of the invention.

Claims (2)

 1. Fluidized bed r-cooled and deep, with exchange surfaces immersed in the bed, characterized in that the vertical collectors (1), to which are connected the tubes (2) constituting the horizontal layers are arranged outside of the combustion chamber (3), and are provided with special narrow flanges (4), and in that the screen (8), tubes with vertical fins (6) embedded in refractory concrete (7) present, at the level of the outlet of the horizontal tubes (2), a gap (5) between the tubes of the screen (8) allowing the passage of the flanges (4) of the vertical collectors (l), which are connected at their upper part by means of a flange elbow (9) on the screen (8).  2. Fluidized bed according to claim 1, characterized in that the openings for the passage of the tubes (2) are obstructed by means of refractory concrete (7), and the sealing of the combustion chamber is completed by a lining. outside (10) made of sheet metal fixed to the screen by means of spacers (11) integral with the fins of the vertical tubes (6) of the screen (8).