GB2037959A - Gas distributor - Google Patents

Abstract

A sparge pipe (1) for use as a gas distributor in a fluidised bed is provided with a plate (6) secured to its top margin in such a manner as to afford resistance for the pipe (1) to thermal distortion during use. Perforations (10) are located along lower margins of the pipe wall and further perforations are provided in the wall just beneath the plate (6). <IMAGE>

Description

SPECIFICATION Gas distributor This invention concerns an improvement in or relating to a gas distributor suitable for use in a fluidised bed.

Where a fluidised bed is employed for the combustion of fuel or other material, the various components in contact with the bed are subject to a high temperature environment and can accordingly suffer from thermal stressing. This can have a deleterious effect on the operating efficiency of the bed.

Sparge pipes for the introduction of fluidising gas into the bed are well known and widely used in fluidised bed technology, but when utilised in an environment working at elevated temperatures, it has been found that there is a tendency for bending to occur.

An object of the invention is therefore to provide a sparge pipe which can operate at high temperatures substantially without the attendant problems caused by thermal stressing.

Accordingly the invention provides a sparge pipe having perforations along at least part of its length, and an elongate member secured along at least part of a top edge of the pipe.

Conveniently the elongate member is a bar or a plate which may be secured to the pipe by means of welding. As a preference the elongate member is stitch welded to the pipe.

The perforations are provided in the pipe in the vicinity of the lower edge thereof. Further perforations may, however, advantageously be located along the pipe subjacent the elongate member.

By way of example only, one form of sparge pipe according to the invention is described below with reference to the accompanying drawings in which: Figure 1 is a side view; and Figure 2 is an end view.

Referring to Figures 1 and 2, a sparge pipe is shown at 1 having an open end 2 and a closed end 4. A plate 6 is stitch welded along the top edge of the pipe 1 as shown and extends from the closed end 4 towards the open end 2 terminating short thereof.

The pipe 1 is perforated in the relatively lower half, as viewed in the drawings, in two rows at 10.

Further perforations 12 are provided in two rows in the vicinity of and subjacent to the plate 6.

The plate 6 serves to stiffen the pipe 1 but is sufficiently flexible to compensate for thermal stressing in the high temperature environment normally obtaining in a fluidised combustion bed.

It has been found that the pipe 1 with the plate 6 maintains substantial straightness during use thus obviating the difficulties previously experienced with conventional sparge pipes. Furthermore, the plate 6 has enabled the provision of additional perforations 1 2 which are shielded by the plate in use, from the ingress of fluidised material.

Hitherto, perforations only in the lower half of the sparge pipe were practical forfuidised beds because of the possibility of entry of bed material thereinto.

The present invention, therefore, represents an important and useful departure from the art and affords the opportunity of successful fíuidised bed operation using sparge pipes. 1

CLAIMS 1. A sparge pipe having perforations along at least part of its length, and an elongate member secured along at least part of a top edge of the pipe.

2. A sparge pipe according to claim 1 in which the elongate member is a bar or plate.

3. A sparge pipe according to claim 2 in which the bar or plate is welded to the pipe.

4. A sparge pipe according to claim 3 in which the bar or plate is stitch welded to the pipe.

5. A sparge pipe according to any one of the preceding claims in which the perforations are provided in the pipe in the vicinity of the lower edge thereof.

6. A sparge pipe according to claim 5 in which further perforations are provided and are located along the pipe subjacent the elongate member.

7. A sparge pipe substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (7)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Gas distributor This invention concerns an improvement in or relating to a gas distributor suitable for use in a fluidised bed. Where a fluidised bed is employed for the combustion of fuel or other material, the various components in contact with the bed are subject to a high temperature environment and can accordingly suffer from thermal stressing. This can have a deleterious effect on the operating efficiency of the bed. Sparge pipes for the introduction of fluidising gas into the bed are well known and widely used in fluidised bed technology, but when utilised in an environment working at elevated temperatures, it has been found that there is a tendency for bending to occur. An object of the invention is therefore to provide a sparge pipe which can operate at high temperatures substantially without the attendant problems caused by thermal stressing. Accordingly the invention provides a sparge pipe having perforations along at least part of its length, and an elongate member secured along at least part of a top edge of the pipe. Conveniently the elongate member is a bar or a plate which may be secured to the pipe by means of welding. As a preference the elongate member is stitch welded to the pipe. The perforations are provided in the pipe in the vicinity of the lower edge thereof. Further perforations may, however, advantageously be located along the pipe subjacent the elongate member. By way of example only, one form of sparge pipe according to the invention is described below with reference to the accompanying drawings in which: Figure 1 is a side view; and Figure 2 is an end view. Referring to Figures 1 and 2, a sparge pipe is shown at 1 having an open end 2 and a closed end 4. A plate 6 is stitch welded along the top edge of the pipe 1 as shown and extends from the closed end 4 towards the open end 2 terminating short thereof. The pipe 1 is perforated in the relatively lower half, as viewed in the drawings, in two rows at 10. Further perforations 12 are provided in two rows in the vicinity of and subjacent to the plate 6. The plate 6 serves to stiffen the pipe 1 but is sufficiently flexible to compensate for thermal stressing in the high temperature environment normally obtaining in a fluidised combustion bed. It has been found that the pipe 1 with the plate 6 maintains substantial straightness during use thus obviating the difficulties previously experienced with conventional sparge pipes. Furthermore, the plate 6 has enabled the provision of additional perforations 1 2 which are shielded by the plate in use, from the ingress of fluidised material. Hitherto, perforations only in the lower half of the sparge pipe were practical forfuidised beds because of the possibility of entry of bed material thereinto. The present invention, therefore, represents an important and useful departure from the art and affords the opportunity of successful fíuidised bed operation using sparge pipes. 1 CLAIMS

1. A sparge pipe having perforations along at least part of its length, and an elongate member secured along at least part of a top edge of the pipe.

2. A sparge pipe according to claim 1 in which the elongate member is a bar or plate.

3. A sparge pipe according to claim 2 in which the bar or plate is welded to the pipe.

4. A sparge pipe according to claim 3 in which the bar or plate is stitch welded to the pipe.

5. A sparge pipe according to any one of the preceding claims in which the perforations are provided in the pipe in the vicinity of the lower edge thereof.

6. A sparge pipe according to claim 5 in which further perforations are provided and are located along the pipe subjacent the elongate member.

7. A sparge pipe substantially as hereinbefore described with reference to Figures 1 and 2 of the accompanying drawings.