EP0195443A1 - Apparatus for separating moisture from and for reheating steam by heat exchange - Google Patents

Abstract

Steam drying and superheating device with a horizontal axis, comprising inside a cylindrical shell a) in its lower part, a chamber for the admission of wet steam, b) above, separating members ( 7, 8, 9, 10, 21) for removing water, c) in its upper part, bundles of superheater tubes 11 and d) on either side of these bundles, channels 15, 17 of circulation of wet steam. These channels are separated from the intake chamber by a partition (19) arranged on one side of the superheaters only, so that the humid vapor rises in the vicinity of the surface of the shell only from one on the sides of the superheaters, then descends on the other side towards the admission to separating members (21).

Description

• a) dans sa partie inférieure, une chambre d'admission de la vapeur humide à sécher et surchauffer,
• b) au-dessus de la chambre d'admission, des organes séparateurs éliminant l'eau de la vapeur humide à surchauffer,
• c) dans sa partie supérieure, des faisceaux de tubes constituant les surchauffeurs, dans lesquels de la vapeur surchauffée sous pression est refroidie, puis condensée en échange de chaleur avec la vapeur séchée à surchauffer,

et d) de part et d'autre des faisceaux de tubes surchauffeurs, des canaux de circulation de la vapeur humide permettant à une partie de celle-ci de s'élever au voisinage de la surface interne de la virole, avant de revenir vers les organes séparateurs,The present invention relates to a device for drying and then overheating by heat exchange, with a horizontal axis, in particular for supplying water vapor to an expansion turbine, comprising inside a cylindrical shell, arranged parallel to its axis and symmetrically with respect to its longitudinal plane of symmetry,

• a) in its lower part, a humid steam inlet chamber to be dried and overheated,
• b) above the intake chamber, separating members eliminating the water from the humid steam to be overheated,
• c) in its upper part, bundles of tubes constituting the superheaters, in which superheated steam under pressure is cooled, then condensed in exchange for heat with the dried steam to be superheated,

and d) on either side of the bundles of superheater tubes, channels for the circulation of wet steam allowing part of it to rise in the vicinity of the internal surface of the shell, before returning to the separating bodies,

Patent EP-B-005225 of the Applicant relates to a device of this kind, in which the channels allow the humid vapor to rise on either side of the superheaters in the vicinity of the internal surface of the shell, then to descend between two groups of superheaters to lead to the inlet of the separators in the vicinity of the plane of symmetry.

Such a device requires that the superheaters be divided into two groups separated by a central space allowing the descent of the wet steam. This requires giving the device a larger diameter, to the detriment of its size and its cost.

The object of the present invention is to provide a device for drying and overheating vapor of reduced bulk and weight than the known device, while ensuring cooling of the internal wall of the shell as effectively.

The device according to the invention is characterized in that its channels for the circulation of wet steam are separated from the chamber intake by a partition arranged on one side of the superheaters only, so that the humid vapor rises in the vicinity of the internal surface of the shell only on one side of the superheaters, then descends from the on the other side towards admission to separating bodies.

It is described below, by way of example and with reference to the single figure of the accompanying drawing, a device for drying and superheating water vapor according to the invention, associated with an installation for producing energy by water vapor expansion in turbines.

The figure shows the device in section through a plane perpendicular to its axis, in line with the pipes for the admission of wet steam and the discharge of superheated steam.

It has an external shroud 1, fitted with wet steam intake pipes (water and steam emulsion) such as 2.

Above a pipe 2, a distribution member 3, such as that which was the subject of patent FR-B-2442069 of the Applicant, distributes the wet steam in two lateral flows represented by the arrows 4 and 5 , and an axial flow represented by the arrow 6. From the left lateral flow, a first part penetrates into the blocks of separating members 7, formed for example by stacks of parallel corrugated sheets, on which the water droplets are deposited, then run off, before being evacuated by gutters and evacuation pipes, not shown.

The right lateral flow of wet steam, represented by arrow 5, enters the separator member blocks 8. The axial flow, represented by arrow 6, enters the separator member blocks 9 and 10.

The dried steam coming from the different blocks of separating members, to which another fraction of dried steam which has served to cool the shell meets, as will be described below, rises to the overheating exchangers 11, formed by tubular bundles inside which higher pressure steam circulates. It crosses these exchangers as shown by the arrows 12, and goes to use by outlet pipes such as 13.

A fraction of the wet steam does not pass directly into the separating members, but rises along the shell 1, as shown by the arrow 14, in a channel 15 disposed between the shell 1 and an internal envelope 16 delimiting the flow of steam to be superheated. This fraction keeps the shell 1 at a relatively low temperature. It then descends on the other side of the internal envelope 16 by a channel 17 along the right side of the shell 1, as shown by the arrow 18. It is then directed by a partition 19 in a channel 20 towards the admission to separating bodies 21, where it gets rid of its residual moisture. This dried fraction then joins the main dried vapor fraction to go to the overheating exchangers.

Claims (1)

Device for drying and superheating steam by heat exchange, with a horizontal axis, in particular for supplying water vapor to an expansion turbine, comprising inside a cylindrical shell, arranged parallel to its axis and symmetrically with respect to its longitudinal plane of symmetry, a) in its lower part, a humid steam inlet chamber to be dried and overheated, b) above the inlet chamber _j of the separating members (7, 8, 9, 10, 21) eliminating the water from the wet steam to be overheated, c) in its upper part, bundles of tubes (11) constituting the superheaters, in which superheated steam under pressure is cooled, then condensed in exchange for heat with the dried steam to be superheated,
and d) on either side of the bundles of superheater tubes, channels (15, 17) for circulation of the humid vapor allowing a part of it to rise in the vicinity of the internal surface of the shell, before returning to the separating bodies,
characterized in that the channels are separated from the intake chamber by a partition (19) arranged on one side of the superheaters only, so that the humid vapor does not rise in the vicinity of the internal surface of the shell on one side of the superheaters, then down on the other side towards the admission to separating members (21).

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