FR2474145A1 - Suspension bracket for industrial boiler water tubes - has tubes welded along steel strips suspended on vertical channels - Google Patents

Abstract

The boiler tubes (1) are welded together using flat steel spacers (2) to form a solid screen wall. The screen wall is supported on suspension units (3). These comprise a vertical channel with a web (4) and flanges (5) with side sections (6) in the form of staples. These are welded to both the spacers (2) between the tubes and to the flanges (5) of the vertical channel. The dimensions and thicknesses of the components of the suspension are designed so that at the operating temperature of the boiler, and during the periods of temperature variation, the differential expansion between the tube wall and the suspension unit, is minimal.

Description

Hanging device for boiler tubes
The present invention relates to a suspension device for boiler tubes with spiral screens.

It is known that in industrial boilers of this type, the tubes in which a fluid which can be brought to a high temperature circulates, are in the form of bundles subject to a holding member called suspension.

In general, such a suspension is in the form of a common type profile to which the tubes are connected by welding or by any other suitable means.

However, it can be seen that the use of such suspensions results in temperature gradients which cause. thermal stresses, especially when the tubes carry fluids subjected to rapid temperature variations. Such thermal stresses can cause deterioration of the connections between tubes and suspensions after a certain time.

The present invention overcomes the drawbacks shown schematically in the above, and it relates to a reliable suspension device for boiler tubes, such a device being of a simple structure and a low cost price.

The invention therefore relates to a suspension device for boiler tubes with spiral screens joined between them by means of fins, suspension whose cross section has the shape of a U formed of a central part or core and of two wings, characterized in that said core as well as said wings have predetermined sections as a function of the temperature as well as of the temperature variation of the fluid circulating in said tubes, said wings being attached to said core by welding.

Other characteristics and advantages of the invention will emerge from the description which follows, given by way of purely illustrative example but in no way limiting with reference to the appended drawings in which
Figure 1 shows in elevation a suspension device for boiler tubes according to the invention.

 FIG. 2 represents a section along the axis II-II of FIG. 1.

 FIG. 3 represents a section along the axis III-III of FIG. 2.

 With reference to the figures, 1 indicates tubes in which a fluid circulates, these tubes being joined between them by means of fins 2 welded to the tubes. Reference 3 designates the suspension to which said tubes are linked.

This U-shaped section suspension comprises a central part or core 4 as well as two wings 5 which are welded to it perpendicularly. It can also be seen in the figures that said tubes 1 are linked to the suspension 3 by means of parts 6 called jumpers welded on the one hand to the fins 2 and on the other hand to the wings 5 of the suspension 3 such welds being materialized at 7. According to the invention, the friend 4 as well as the wings 5 of the suspension 3 have predetermined sections as a function of the temperature as well as of the variation of the temperature of the fluid circulating in the tubes 1, so that the thermal stresses at the level of said suspension have a low value. More precisely, such a choice of dimensions of the friend 4 and the wings 5 allows their identical heating on the one hand by radiation of the tubes 1 on the core 4 and on the other hand by thermal conduction of the calories transmitted by the jumpers 6 to the wings 5.

 We will give below a concrete example of a suspension according to the invention.

The fluid circulating in the tubes 1 has a temperature variation from 150 to 3500C - and at a speed of the order of 50C to 60C per minute.

 The size of the jumpers 5 is 50 x 50 x 5 mm.

Under these conditions, suspension 3 is given the following dimensional characteristics:
Width of train 4: 210 mm
Thickness of friend 4: 5 mm
Wing length 5: 50 mm
Wing thickness 5: 10 mm
Although the device which has just been described seems the most advantageous for the implementation of the invention in a particular technical situation, it will be understood that various modifications can be made to it without departing from the scope of the invention, some of its elements which can be replaced by others capable of ensuring the same technical function.

Claims (3)

1 / Suspension device for boiler tubes with spiral screens joined between them by means of fins, suspension whose cross section has the shape of a U formed by a central part or core and by two wings, characterized by the fact that said core as well as said wings have predetermined sections as a function of the temperature as well as of the temperature variation of the fluid flowing in said tubes, said wings being added to said core by welding. 2 / Device according to claim 1, characterized in that said tubes are connected to the suspension by means of jumpers welded on the one hand to the wings of the suspension, and on the other hand to said fins. 3 / Boiler comprising at least one suspension device according to one of claims 1 or 2.