KR830001408B1 - Liquid and gaseous separators for fluids - Google Patents

Abstract

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Description

Liquid and gaseous separators for fluids

1 is a cross-sectional view showing an upper portion of a steam generator incorporating a separator according to the present invention.

FIG. 2 is a side view showing the shape and arrangement of the blades of the separator of each separator groove of the steam generator shown in FIG. 1 and the folding of one blade of the device.

FIG. 3 is a side view similar to FIG. 2 showing in folded form the shape and arrangement of the feathers of the lower separator of each separator groove as shown in FIG.

4 is a perspective view showing the shape and distribution of the feather in the lower separator of FIG.

The present invention relates to a device for separating liquid and vapor phases of a fluid and to the application of such a device to a reduction in the moisture content of the vapor exiting the steam generator.

Generally, any amount of gaseous fluid is liquid. For many applications, the permissible percentage of fluid in the liquid phase is less than the existing percentage and it is necessary to pass the fluid through a suitable separator that allows the passage of the fluid in the gas phase, most of which remains in the liquid phase carried by the vapor. Let's do it.

Thus, for example, a steam generator that heats water in which the primary heat transfer fluid circulates in the secondary circuit to vaporize the secondary circuit therein generally produces saturated steam with a fairly high content. This is especially true if the primary fluid circulates in a U tube immersed in water in the generator. In this type of steam generator, the steam content of the generated steam varies between 20 and 80% by weight as a function of operating and service conditions. This steam content is not compatible with the maximum steam content allowed in turbines driven by steam exiting the steam generator. Thus, the steam driving the turbine must contain a liquid that does not exceed 0.25%. Therefore, it is necessary to bring about optimal separation of the liquid and gas phase before the steam reaches the turbine. This separation is usually carried out in steam turbines, especially in the upper dome.

Subsequently, a number of separation devices are known which are arranged in the upper dome of the steam generator. These known devices are usually operated by gravity or labyrinth seals and holding channels according to the cyclone principle. However, they all place a large number of these separators in the top dome of the generator, resulting in significantly lower efficiency, a large pressure drop that reduces circulation rate, or an overall dimension that occupies a large area within the generator. Have drawbacks. In all three cases, the overall dimensions of the device or separator in the steam generator are very large and significantly increase the overall height of the generator compared to the actual heat exchanger.

The present invention therefore relates to the manufacture of a device for separating the liquid and gaseous phases of a fluid that can be used in an increasing generator without limiting the overall dimension and pressure drop and having a high efficiency to increase the overall height unproportionally.

The invention also relates to the manufacture of a separator having a simple design and which can be used outside of the steam generator. The present invention therefore relates to a device for separating the liquid and gas phase of a fluid containing a cylindrical wall with a feather disposed therein, wherein each feather is in the form of a triangular curved surface, the first side of which is adjacent to the wall and its axis. The axle defines a coincident spiral, the vertex opposite the first side being disposed in the axis of the wall and assembled as a seal at the corresponding vertex of the other feather and the other side perpendicular to the wall axis and the axis Defines the trailing edge inclined to.

As a result of this special shape of the collar of the separator according to the invention, the device has high efficiency for small overall dimensions. Thus, in most cases using two units of this type nested within the aid of a steam generator yields steam that can be used directly in the turbine.

According to an adopted embodiment of the present invention, the inclination angle of the trailing edge with respect to the wall axis is between 30 and 60 degrees. According to another feature of the invention, the trailing edge of each feather defines a cylindrical surface which is curved inwardly in a spiral direction defined by the first side with a straight line joining the corresponding vertices.

According to a first variant of the invention, the leading edge of each feather is a straight line. According to a second variant of the invention, each feather has a frustum shaped extension which is bent inward in a helical direction defined by the first side on the side of the leading edge, the radius of the curved surface of the extension increasing towards the cylindrical wall. do.

Preferably, the liquid fluid retained in the device is discharged by an annular cover located in an extension of the cylindrical wall on the fluid discharge side and by a cylindrical skirt whose diameter exceeds the diameter of the wall extending the annular cover. The inner diameter is smaller than the wall diameter.

The invention is particularly applicable to steam generators of the type consisting of an outer casing, a first circuit in which a high temperature primary fluid circulates and a second circuit in which a secondary fluid circulates, wherein the secondary fluid is a liquid phase And a means for separating the liquid and gaseous phase of the secondary fluid located around the outlet from the casing after storing the calorie portion transferred into the casing and transported by the primary fluid. The separating means comprises at least one groove of two separating devices.

Preferably, the wall of the second separator is sealably connected to the cover of the first separator. For satisfactory operation of the generator, the second circuit consists of an upper chamber for generating a second separator therein and a chamber for creating a defined passage between the walls of each separator and the corresponding cylindrical skirt therein. The chamber is linked by drying means having a low pressure drop.

According to an embodiment adopted in the present invention, each feather of the first separating device on the leading edge side is composed of a frustum shaped extension which is bent inward in a spiral defined by the first side, the curved radius of which is Increased toward the corresponding cylindrical wall and the leading edge of each feather of the second separator is straight. The invention is described in more detail below with reference to the accompanying drawings and non-limiting embodiments.

The steam generator, shown at its top in FIG. 1, is a known structure in which a hot primary fluid circulates in a U tube groove to transport calories carried by a secondary fluid, usually water. This generator comprises a cylindrical outer casing 12 of vertical axis, a tightly sealed partition 14 enclosing the groove 14 of the tube 10 in the casing 12 and a chamber formed in the top of the casing 12. It has two overlapping separators 16 and 18 repuups associated with the grooves of the tubes 10 for connecting the confined chamber 15 in the corresponding partition 14 with 20). The chamber 20 is provided with an outlet 22 for linking to a use circuit not shown. As shown in FIG. 1, the upper chamber 20 is separated from the chamber 34 in which the separating devices 16 and 18 are received by the drying system 24 therein.

As a result of this arrangement, when the hot primary fluid circulates in the groove of the tube 10 and the secondary fluid penetrates from the bottom into the chamber 15, the secondary fluid is separated from the separator 16 and By continuing to cross 18, it evaporates before entering the chamber 20, which makes it possible to reduce the moisture content of the steam entering the chamber 20 to an appropriate level. The steam exiting chamber 20 via opening 22 is usually advanced into an unshown utilization circuit that incorporates a turbine that converts the thermal energy of the steam into mechanical energy.

According to the invention, each separator 16 and 18 has a cylindrical wall 26 on a vertical axis, an extension of the cylindrical wall on the fluid outlet side, ie an annular cover 28 and an annular arrangement disposed above the wall of the indicated embodiment. It has a cylindrical skirt 30 extending under the cover 28. The inner diameter of the cover 28 is smaller than the diameter of the wall 26, and the outer diameter of the cover 28 and the diameter of the skirt 30 are larger than the diameter of the wall 26. Thus, the cover and the cylindrical skirt define an annular passage 32 whereby the liquid fluid is advanced into the chamber 34 defined in the casing 12 between the porous wall 24 and the closely sealed partition 14.

Separation of the liquid phase and gaseous phase of the secondary fluid circulating through the separators 16 and 18 is performed by the vanes 36 and 38 generating centrifugal action in each device. As shown in FIG. 1, the cylindrical wall 26 of each lower separator 16 is sealably connected to a corresponding partition 14. Equally, the cylindrical wall 26 of the upper separator 18 is connected to the cover 28 of the lower separator 16 and the seal 28 is connected to the tube 40 traversing the porous partition 24. Finally, the separators 16 and 18 are coaxially arranged, as shown in FIG. 1, and the dimensions of the wall 26 and the cover 28 are usually the same.

The arrangement in the separators 16 and 18 corresponding to the particular shapes of the collars 36 and 38 will now be described with reference to FIGS. Each separator 16 and 18 includes six vanes 36 and 38 regularly distributed within the cylindrical wall 26.

For simplicity, we first start with the collar 38 of the upper separator 18 with reference to Figure 2, the shape of which is less complicated than the feather of the lower separator 16.

Each feather 38 is in the form of a triangular curved surface, the first side of which is adjacent to the corresponding wall 26 and defines the helix, the axis of which coincides with the helix axis X-X. The vertex A of this triangular curved surface opposite the side 42 is usually located in axis X-X. According to the invention, the six vanes 38 are assembled to each other hermetically by welding or the like such that secondary fluid does not pass directly through the corresponding separator 18. The two other sides AB and AC of the triangular curve 38 are each perpendicular to the axis XX of the wall 26 and are preferably at an angle between 30 and 60 ° with respect to the axis XX and the leading edge 44 located at the bottom of the wall. Define the inclined trailing edge 46. In the embodiment shown in FIG. 2, this angle usually has a value equal to 45 °.

The leading edge 44 of each feather 38 is preferably straight, the trailing edge 46 is curved and in the spiral direction defined by the side 42 with a straight line AC that joins with the corresponding vertex of the triangular curved surface defined by the feather. Define inwardly, ie upwardly curved cylindrical surface when considering the side view of FIG. Preferably, each feather 83 can be deployed, ie the generatrix of the feather passing through vertex A and side 42 is a straight line. And the trailing edge part 46 of each feather is a bevel shape enjoyably.

The vanes 36 of the lower separator 16 are arranged in the same manner as the vanes 38 of the separator 18, i.e. there are six regularly distributed within the cylindrical wall 26 as shown in FIGS. 3 and 4. do.

The shape of the feather 36 is similar to that of the feather 38. The shape of each feather 36 is similar to the shape of the feather 38. Each feather 36 is in the form of a triangular curved surface, the one side 48 of which is adjacent to the wall 26 defines a spiral, the angle of which coincides with each axis Y-Y of the wall. Equally, the vertex D of the triangular curved surface defined by each feather opposite the side 48 is located primarily in axis Y-Y. As in the case of the upper separator 18, the vanes 36 are welded to each other at the same level as the vertex D as shown in FIG. Two other sides DE and DF of the triangular curved surface defined by each feather 47 constitute the leading edge 50 and the trailing edge 52.

The trailing edge 52 is beveled and bent in the same manner as the trailing edge 46 of the edge of the feather 38. However, the collar 36 is different from the collar 38 by its leading edge 50. Thus, each feather 36 has a frustum shaped extension 54 whose axis is approximately perpendicular to the axis Y-Y on the side of the leading edge 50. The elongate portion 54 is bent inward in the helical direction formed by the side portion 48, that is, toward the bottom in the case of the side views of FIGS. 4 and 3. As shown in Figs. 3 and 4, the radius of curvature of the frustum shaped extension 54 increases from the axis Y-Y towards the cylindrical wall 26. Figs. As with the feather 28, each feather 36 can be deployed.

Operation of the above-described steam generator with reference to FIGS. 1 to 4 is as follows.

Due to the heat exchange between the primary fluid and the secondary fluid in the U tube 10 through which the primary fluid circulates, the secondary fluid is vaporized in the chamber 15 defined in the tightly sealed cylindrical partition 14. . The gaseous secondary fluid has a fairly high moisture content between 20 and 80% by weight at the top level of chamber 15. It then continues to cross separators 16 and 18 before entering the upper chamber 20 in the tube 40. The dried steam is then discharged from outlet 22 to a utilization circuit (not shown).

Steam entering by the lower end of each separator 16 and 18 is spiraled such that a liquid secondary fluid deposits on the inner surface of the cylindrical wall 26 before advancing into the chamber 34 via the passage 32. Centrifugal force is applied by the quills 36 and 38. The moisture content of the steam flowing out of the chamber defined in the partition 14 is reduced by each separator 16 and 18 such that the moisture content of the steam contained in the chamber 20 is 0.25% or less by weight.

A small amount of steam may enter the chamber 34 via the passage 32. The gaseous fluid entering chamber 34 is recovered after crossing the drying system 24 containing all or part of the droplets without generating a significant pressure drop in the outgoing vapor. For example, system 24 consists of a porous bulkhead made of a commercially available product known under the trade name “KNIT”. Drying is carried out by gravity or other drying systems (such as impact or labyrinth dryers).

From the foregoing, it has been found that the separators 16 and 18 according to the invention have a sufficiently high efficiency at the bottom so that the two series connected separators can reduce the moisture content of the steam exiting the steam generator to an appropriate level. Could be. The overall dimensions of the steam generator are significantly reduced compared to that of conventional separators.

Apparently, the present invention is not limited to the embodiments described above by way of example, and in fact covers all modifications thereof. Thus, the device for separating liquid and gas phases according to the present invention can be used whenever such separation is required and the use of steam generators in the above manner is not limited.

Claims (1)

Each feather is in the form of a triangular curved surface, the first side of the adjoining wall defining a helix whose axis coincides with the wall axis, the vertex opposite the first side being disposed in the axis of the wall and the Separating liquid and gaseous phases of the fluid containing a cylindrical wall with a feather therein, the seal being assembled at a corresponding vertex and the other side defining a leading edge perpendicular to the wall axis and a trailing trailing edge inclined to the axis. Device for.

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