FI79600B - FASAOTSKILJARE FOER EN TVAOFASBLANDNING I RINGSTROEMMAR. - Google Patents

Description

1 79600

Phase separator of a two-phase mixture of ring flows

The present invention relates to a phase separator according to the preamble of claim 5.

In many systems, it is necessary to separate the phases of the liquid / gas mixture flows present in them.

10 For example, in steam turbine equipment, this is particularly necessary to minimize the erosion and corrosion potential of the water / water vapor flow in them, to reduce the pressure drop in the pipelines, and to avoid shocks in the system. In most cases, the heat exchangers connected downstream of the steam turbine device 15 are not suitable for the flow-through of a two-phase mixture, or the systems are not designed accordingly.

Often such biphasic flows consist of cardiac and 20 ring flows, i. the liquid phase forms a closed membrane in the wall of the tube which completely surrounds the gaseous phase flowing inside the core. The wall membrane can account for up to 80% of the total liquid mass flow.

25 Steam turbine units use the following measures for phase separation of the two-phase mixture, together or separately - installation of simple bounce plates - placement of Pelton blades 30 - installation of reversing separators - use of a cyclone separator

What all these measures have in common is the disadvantage that the phase separation already carried out in the ring flow does not in itself form the starting point for the separation of the phases from one another, but that the two phases are remixed with one another. The droplets formed are then separated on the one hand by gravity 2 79600 (bounce plates, Pelton wings) and on the other hand by centrifugal forces (rotary separators, cyclone).

The former solution requires a strong expansion of the flow cross-section 5 in order to reduce the bounce rate, which further causes the traction force of the steam or gas to be reduced. Another solution requires a strong circulation of the flow in connection with the cyclone.

It is known from FR-2 357 818 to derive the separation of the liquid part from the two-phase mixture by circulating motion. In principle, this involves centrifuging the liquid / gas mixture. This achieves that the liquid part of the mixture descends along the wall of the pipeline leading to the mixture, whereby it can be further separated downstream. In the device sense, the separation takes place by connecting a concentric pipe to the pipeline, whereby the liquid part is led out through the ring bushing created between the two pipes. The opening of the ring bushing is then accurate in size: the bushing is optimal:: 20 only when the liquid film of the wall can be absorbed. Too small an opening means insufficient fluid separation. and too large an opening will allow unwanted steam to enter. Centrifugation of the mixture is hampered by the lack of homogeneity of the wall membrane itself. Thus, it is expected that the desired separation of the biphasic mixture will be labile. In this case, it is expected that the separation of the two-phase mixture may collapse together because no measures have been taken against the dam pressure potentially forming in the gas-carrying pipe. The measures are, on the other hand, relevant in so far as such a phenomenon is capable of breaking the wall in the region of the annular passage of the liquid film. Further steps must be taken to ensure that the portion of the liquid which does not separate in the annular passage and which entrains on the downstream side can be separated from the laminar gas stream formed in the meantime without repeating measures.

Il 3 79600 Here the invention provides an improvement. The object of the invention, which is characterized by the claims, is to prevent the liquid wall membrane and the gas core flow from being diverted after their separation in a phase separator of the type mentioned in its introduction, without the possibility of remixing of the phases.

The object of the invention is to provide functions so that in connection with the discharge of the gaseous phase, no dam pressure can be generated, which could break the liquid film of the wall in the area of the ring bushing. It is a further object of the invention to ensure that any liquid portion which is not separated in the ring passages can still be freshly separated on the downstream side.

15

The advantage of the invention can be seen substantially in that by reversing the gas core flow downstream of the ring passage and parallel above the underlying water collector, the damming pressure caused by the gas flow bounce is avoided. Thanks to this reversal, it is a further advantage that the liquid portions remaining in the gas core flow can be separated well and simply by the naturally occurring central exhaust effect in the bend without having to intervene in the gas core flow by far-reaching measures.

r: 25

In the following, embodiments of the subject of the invention are shown in a simplified form by means of a drawing and will be explained in more detail. Not all elements irrelevant to the understanding of the invention have been presented. Flow direction of media: 30 is indicated by arrows.

In the drawing, Figure 1 shows a phase separator according to the invention for a two-phase mixture.

Figure 1 shows a greatly simplified plan for the phase separation of a two-phase mixture in a flow in which the phases of the mixture 3 are already introduced in a layer. Thus, the liquid phase 6 of the 4 79600 mixture forms a membrane (liquid wall membrane) closed to the pipe wall of the pipeline 7 conducting the two-phase mixture, which completely surrounds the gaseous phase 4 flowing inside (gas core flow). In the mouth area 1 of the liquid collector 2 there is a concentric inner tube 5 placed in the pipe 7 of the pipe 5, the ring passage 12 of which keeps a distance from the pipe 7.

It corresponds to the thickness of the liquid wall film 6. When the gas core flow 4 flows through the inner tube 5 and is turned sideways above the liquid collector, the liquid wall membrane 6 can flow 10 unobstructed through the ring bushing 12. After the separation of the two-phase mixture 3, the phases 4 and 6 no longer come into contact with each other, so that the dreaded remixing is not possible. Turning the inner tube 5 downstream and parallel above the liquid collector 2 prevents any dam pressure in the gas core flow 4. This avoids the breakage of the labile liquid wall membrane 6 in the region of the ring passage 12, which consequently eliminates the need for phase separation of the mixture 3. The bend of the inner tube 5 further acts in such a way that the liquid portion remaining in the gas core flow 4 mainly in the separation area can be separated by the naturally occurring centrifugal effect of the bend both well and simply, i.e. "freshly", i.e. without the gas core flow. 4 must be addressed by far-reaching measures.

Λ 25 li