WO2009054021A1

WO2009054021A1 - System for regenerating filters of a filter chamber for aeriform substances

Info

Publication number: WO2009054021A1
Application number: PCT/IT2008/000660
Authority: WO
Inventors: Sauro Di Nardo
Original assignee: S.E.I.C.O. Impianti S.R.L.
Priority date: 2007-10-24
Filing date: 2008-10-22
Publication date: 2009-04-30
Also published as: ITAN20070025U1

Abstract

A system (1) for regenerating the operation of filters in a filter chamber (3) for aeriform fluids, in particular for filtering air used to feed a gas turbine plant, comprises at least one afferent air pipe (4), and at least two deferent pipes (5) connected to the same afferent pipe (4) and having a diffuser (6) at their free end. Each afferent pipe (4) and the respective deferent pipes (5) are connected to each other at a reciprocal join zone (9) with axes (4a, 5a) at right angles to each other. Each deferent pipe (5) has a single curved stretch (10), which is distal from the zone (9) of the connection to the afferent pipe (4).

Description

System for regenerating filters of a filter chamber for aeriform substances

Technical Field

The present invention relates to a system for regenerating the operation of filters in a filter chamber for aeriform substances, in particular for gas turbine plant filter chambers.

Background Art

As is known, the air which supplies a gas turbine plant must be filtered before it enters the plant. For said purpose there are prior art filtering systems comprising a filter chamber housing filters for filtering the air fed into the plant.

The filters of said systems are subjected to periodic maintenance which involves restoring full filter operation by cleaning them and removing particulate caught. This is done by blowing compressed air on the filters in the direction opposite to the normal direction of feed of the gas turbine plant.

In general, the filter regenerating system comprises sets of compressed air feed pipes, their ends fitted with diffusers which blow the compressed air onto the filter chamber filtering panels.

A prior art solution of said type basically comprises four independent parallel feed pipes which pass through the filter chamber in a straight line, extending along a subsequent curved stretch, in particular bent twice at 90°, and ending with the diffusers opposite the filters, located at a suitable distance from them, and angled in such a way that they cause the air to flow out in the opposite direction to the direction in which the feed pipes run.

The four parallel feed pipes are in turn fed by a splitting connector (commonly known as a splitter) which feeds the feed pipes two by two through division, towards the feed pipes, of a single flow of air received at infeed by the splitter. Moreover, the four parallel pipes are interconnected by means a spacer plate inserted between them which substantially has the shape of a quadrilateral with straight sides. The pipes are in tangential contact with the plate and are welded to the sides of the plate at a limited zone in which the circular outline of the pipe is at a tangent to a straight side of the plate. The above-mentioned solution, although used for a long time and with satisfactory results, is not without some disadvantages which limit its technological quality, its performance quality, and which also have a negative effect on production costs.

A first disadvantage can be recognised in the typical shape of the curved stretches upstream of the diffusers.

The need to bend each feed pipe twice at 90° entails the following: on one hand, high pipe processing costs; and on the other hand, overall permanent sets and distortions of the pipe which, despite the contribution of some elastic return components in the material of which it is made, may have a negative impact on the precision of final positioning of the diffusers relative to the filters.

It is known that in the particular sector of gas turbine plant, the quality of the removal of dust from the air is essential. Equally essential is the effectiveness of filter cleaning. In light of these aspects, the distance and position of the diffusers relative to the filters play a fundamental role as regards cleaning effectiveness, to such an extent that they are subject to quite restricted size tolerances. Since it is also known that production errors increase with increases in the number of curves to be made in the pipe, it is obvious how production quality can affect the quality of operating performance, since the latter is also influenced by the more or less complex shape of the pipe and the level of precision which can effectively be achieved for it, that is to say, regarding the position of the diffuser carried by the pipe relative to the filter from which dust must be removed.

A second disadvantage of the prior art is due to the presence of the "splitters". These considerably complicate construction due to their curved shape, which is difficult to produce, with construction also being affected by the additional disadvantage that they are geometrically bulky. Moreover, partly due to their length, the presence of the splitters makes the structure as a whole heavier.

Another disadvantage of the prior art is that of having limited construction strength, particularly in the zone where the plate is connected to the pipes for feeding air to the diffusers. Said connection zones are not very large, meaning that the welds forming the connection may have limits which compromise their effectiveness and the life of the join.

Disclosure of the Invention

The aim of the present invention is to overcome said disadvantages with a filter cleaning system designed in such a way that the pipes do not have splitters; the shape is relatively simple with the minimum number of curves; the pipes weigh less; with a sturdy, reliable structure.

In accordance with said aims, a solution which achieves those results is provided by a system with the technical characteristics which may be inferred from the content of the claims herein, in particular in claim 1 and any of the claims directly or indirectly dependent on claim 1.

Brief description of the drawings

The technical solution is described in detail with reference to the accompanying drawings, which illustrate a preferred embodiment of the invention by way of example only, without in any way limiting the scope of the invention, and in which:

Figure 1 is a side assembly view of a system for regenerating the operation of filters in a filter chamber, in accordance with the present invention; Figure 2 is an elevation view of a system in accordance with the invention, seen from the direction "X" in Figure 1 ;

Figure 3 is a top plan view of the system shown in Figure 2.

Detailed Description of the Preferred Embodiments of the Invention With reference to the accompanying drawings, the numeral 1 denotes as a whole a system for regenerating the filters of a filter chamber 3 for aeriform fluids, in particular of a filter chamber 3 for filtering the air fed to a gas turbine electric plant.

The system 1 - which operates intermittently and against the flow of normal gas turbine plant feed - basically comprises a plurality of operating sections 25, each having two afferent air pipes 4, each of which in turn feeds two respective deferent pipes 5 fitted with an end diffuser 6 located at a free end of each pipe 5. The air passes through the system 1 - in the known way - first through the afferent pipes 4 according to the direction of flow indicated by the arrow 17 in Figure 3, then flows out through the diffusers 6 and in an equally known way strikes, as indicated against the normal direction of flow, the filtering panels not illustrated in the accompanying drawings.

Each afferent pipe 4 is connected to a pair of corresponding deferent pipes 5 in a reciprocal join zone 9 in which the pipes 4 and 5 have respective axes 4a and 5a at right angles to each other and substantially forming a horizontal connection plane

(with reference to Figures 1 and 2) relative to which the afferent pipe 4 and the deferent pipes 5 are coplanar with each other.

In more detail, relative to the join zone 9, each deferent pipe 5 has a suitably curved distal stretch 10 which in particular is the only curved stretch 10 of each of the deferent pipes 5.

Figure 3 shows how the curved stretch 10 preferably subtends a right angle. ha the join zone 9 the connection of each afferent pipe 4 to the two deferent pipes 5, on either side of it, is made with a preformed union tee 15 having right- angle ways. Figure 2 also shows how the deferent pipes 5 also have oblique stretches 12, set at an angle to the horizontal connection plane 4a and 5a.

The oblique stretches 12 are preferably angled with a bending angle 13 whose amplitude is contained in a suitable range around an angle having a nominal amplitude of 20°. Figure 2 also shows how the oblique stretches 12 of deferent pipes 5 are angled with angles 13 extending in opposite directions in the two half-spaces at the sides of the corresponding afferent pipe 4. This is so that all of the system 1 diffusers 6 can be arranged on a shared line 14, substantially parallel with the join zones 9 plane 4a and 5a, as is clearly shown in Figure 2. There is also a plate 16 - visible in Figures 2 and 3 - for connecting the two afferent pipes 4 of each operating section 25. In particular, said plate 16 has zones for connecting the afferent pipes 4 which are shaped to match the outer outline of the pipes 4.

The plate 16 made in this way allows the connection to be made with relatively long weld beads so as to give the system 1 a sturdy single-block structure which is lasting and reliable.

The technical solution designed in this way achieves the result of providing a structure for the pipes which, compared with the prior art, advantageously is without splitters; which is simpler to make and is lighter (partly because the pipe paths are more direct and shorter). The T-shaped join zones 9 also give a high degree of structural stiffness with reduced weight and more compact dimensions.

Moreover, the shape of the system 1 which has a minimum number of parts formed with permanent set: a single 90° curve and a single bend - preferably at 18° - for each section 25, is simpler and more economical to make, can be produced with greater precision and, being less subject to more or less uncontrollable distortion, is made in a more precise and repeatable way.

The technical solution in accordance with the invention is susceptible of industrial application and may be modified and adapted in several ways without thereby departing from the scope of the inventive concept. Moreover, all details of the invention may be substituted by technically equivalent elements.

Claims

1. A system for regenerating the operation of filters in a filter chamber (3) for aeriform fluids, in particular for filtering air used to feed a gas turbine plant, the system (1) comprising at least one afferent air pipe (4), and at least two deferent pipes (5) connected to the same afferent pipe (4) and having a diffuser (6) at their free end; the system (1) being characterised in that the one or each afferent pipe (4) and the deferent pipes (5) are connected with axes (4a, 5a) at right angles to each other at a reciprocal join zone (9); each deferent pipe (5) having a single suitably curved stretch (10), distal from the zone (9) of the join to the afferent pipe

(4).

2. The system according to claim 1, characterised in that the curved stretch (10) subtends a right angle.

3. The system according to claim 2, characterised in that said one or each afferent pipe (4) and the respective deferent pipes (5) form a reciprocal connection plane (4a and 5a) at their join zone (9), the deferent pipes (5) also having stretches (12) which are oblique relative to the connection plane (4a and 5a).

4. The system according to claim 1 or 3, characterised in that the oblique stretches (12) are angled with a bending angle (13) whose amplitude is contained in a suitable range around an angle having a nominal amplitude of 20°.

5. The system according to claim 4, characterised in that the oblique stretches (12) of the deferent pipes (5) are angled with angles (13) in opposite directions designed to position the diffusers (6) on a shared line (14) substantially parallel with the connection plane (4a and 5a).

6. The system according to any of the foregoing claims, characterised in that it comprises a union tee (15) which connects the afferent pipe (4) and the deferent pipes (5) to each other.

7. The system according to any of the foregoing claims, characterised in that it comprises two afferent pipes (4), each feeding two respective deferent pipes (5).

8. The system according to claim 7, characterised in that it comprises a plate (16) for connecting the afferent pipes (4) to each other.

9. The system according to claim 8, characterised in that the plate (16) has zones for connection of the afferent pipes (4), said zones being shaped to match the outline of the pipes (4). _c

10. A system (1) comprising a plurality of operating sections (25), each comprising at least one afferent air pipe (4), and at least two deferent pipes (5) connected to the same afferent pipe (4) and having a diffuser (6) at their free end; the system being characterised in that the one or each afferent pipe (4) and the deferent pipes (5) of an operating section (25) are connected with axes (4a, 5a) at right angles to each other at a reciprocal join zone (9); each deferent pipe (5) having a single suitably curved stretch (10), distal from the zone (9) of the join to the afferent pipe (4).