RU2446860C2 - Device for cleaning steam or gas from foreign impurities - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to power engineering and may be used at high- and medium-pressure steam pipelines after superheating at electric power stations that feature steam turbine blading section abrasive wear from scale particles. Proposed cleaner comprises pipeline accommodating Venturi nozzle, separation chamber and foreign impurities collector. Separation chamber is formed between pipeline and Venturi nozzle with its inlet part jointed to pipeline inner surface at their contact point and its divergent section is jointed all over tube inner diameter. Stiffness ribs are welded to Venturi nozzle inlet. Venturi nozzle diameter in divergent section equals that of pipeline while Venturi nozzle axis is displaced from pipeline axis. Separation grid is fitted at separation chamber inlet.

EFFECT: higher degree of cleaning, simplified design, ease of use.

3 dwg

Description

The invention relates to the field of energy and can be used on steam pipelines of high and medium pressure after superheating in those power plants where abrasive wear of the flow parts of high and medium pressure of steam turbines from scale particles occurs, which due to the formation and subsequent destruction of the oxide film in the boiler outlet ducts are transported by steam to the flow part of the turbine.

Known separation devices that are located on a section of the pipeline when changing direction near the knee and use the inertial principle, as a result of which foreign particles are concentrated in the wall layer of the pipeline when it is rotated and removed from the carrier medium. Such devices include a device for purifying steam or gas of foreign inclusions, including a pipeline, a connection pipe for selecting inclusions with a visor above it, and a chipper located on the pipe wall opposite from the visor and offset from the visor along the axis of the pipeline, and an elbow with inner and outer sides, while the bump is located in front of the inner one, and the sampling pipe is behind the outer side of the knee, a reverse visor is made inside the sampling pipe, behind which the outside a sampling tube is installed covering the sampling nozzle magnet, and between the return visor and the magnet, a circulation pipe is connected to the sampling nozzle connecting it to the pipeline (RU 2213607, IPC 7 B01D 45/08, 45/16, published on 10/10/2003).

The disadvantages of the known device is that the inner diameter of the outlet pipe according to the strength of the pipeline occupies a limited part of the rotation, so most of the particles under the influence of the high-speed flow of the medium goes further down the pipeline. For the same reason, that part of the solid particles that, under the influence of paired vortices in the rotation zone, moves along the peripheral part of the pipe, also passes the separation device. The chipper before turning the flow and the visor behind the entrance to the pipe create increased hydraulic resistance in the pipeline. The action of the circulation pipe to increase the flow with particles into the sampling pipe cannot be effective, since it is connected at the outlet to the pipeline with a higher pressure than at the inlet.

A device for cleaning steam or gas from foreign inclusions is known, which is mounted directly in the pipeline vertically or horizontally in straight sections, including a pipeline and a foreign inclusions storage ring, in which a normalized Venturi nozzle with confuser, cylindrical and expanding sections is installed inside the pipeline, and outside it a housing forming an annular separation chamber with the pipeline and the Venturi nozzle, while the front portion of the separation chamber is in communication with the pipeline annular inlet a diffuser formed with the inner surface of the pipeline and the outer surface of the confluent portion of the Venturi nozzle, and the middle portion of the separation chamber is communicated with a confuser annular channel with the inlet portion of the expanding portion of the Venturi nozzle, in addition, behind the inlet diffuser in the space between the wall of the housing and the outer surface of the wall of the cylindrical section and the walls of the expanding section there is a deflector, and between it and the inlet diffuser there is a spatula, centering the cylindrical section inside the body and (RU 2342973, IPC B01D 45/04, published 10.01.2009). In this known device, the separation of solid particles from steam or gas from a medium that extends along an external circuit is realized by an inertial and gravitational method. The external circuit is designed so that the loss of hydraulic pressure is less than the pressure change in the venturi nozzle to ensure that the purified medium leaves solid particles in the pipeline.

By the totality of the features, this known technical solution is the closest to the claimed one and is taken as a prototype.

A disadvantage of the known technical solution adopted for the prototype, as well as the reason that impedes the achievement of the desired technical result when using the aforementioned known device, is that the product is technically complex, laborious to manufacture, has significant weight and, accordingly, other related indicators, which may limit its use. The effectiveness of a device for purifying steam or gas from solid particles depends on the volume of steam or gas passing through the inlet annular channel, the dimensions of which are limited. The increase in the width of the slotted channel leads to an excessive increase in the nodes of the external contour and the external dimensions of the device, which further aggravates its weight and other related indicators. In addition, an increase in the input also leads to an increase in the pressure loss in the external circuit and, if these losses are equal to the pressure in the Venturi nozzle, the efficiency of removing solid particles from the medium will change for the worse. Moreover, according to its weight characteristics, this product during its operation requires a special suspension device.

The analysis of the prior art by the applicant, including a search by patent and scientific and technical sources of information, as well as identification of sources containing information about analogues of the claimed invention, allowed to establish that the applicant did not find a technical solution characterized by signs identical or equivalent to those proposed.

The definition from the list of identified analogues of the prototype, as the closest technical solution for the totality of features, allowed us to identify in the claimed device a combination of significant distinguishing features in relation to the technical result perceived by the applicant, as set forth in the following claims.

The claimed technical solution allows you to position the proposed device in the pipeline of steam or gas after it is rotated on a horizontal section and fits into the overall dimensions of the pipeline. The device eliminates the external circuit with a storage chamber, which is very laborious in technological design and significantly increases the weight of the device. The claimed technical solution allows to achieve a higher degree of purification of steam or gas. The device is not laborious and not difficult to manufacture and during its operation does not require a special suspension device.

A device for cleaning steam or gas from foreign inclusions is proposed, including a pipeline inside which a Venturi nozzle, a separation chamber and a foreign inclusions storage tank are installed, wherein a separation chamber is formed between the pipeline and the Venturi nozzle, the inlet of which is connected to the inner surface of the pipeline at the point of contact with last, and the expanding part - along the entire inner diameter of the pipe, stiffeners are welded on the inlet of the Venturi nozzle, and the diameter of the Venturi nozzle in the expanding part p Aven to the diameter of the pipeline, and the axis of the Venturi nozzle is deviated from the axis of the pipeline, in addition, a separation grid is installed at the entrance to the separation chamber.

The invention is illustrated by drawings, which depict:

figure 1 - General view of the device;

figure 2 is a view aa of figure 1;

figure 3 is a view of BB in figure 2.

A device for cleaning steam or gas from foreign inclusions is installed on a horizontal section of the pipeline when it is rotated, near the knee and includes a pipe body 1, inside which a Venturi nozzle 2 is installed with an inlet tapering section 3, a cylindrical section 4 and an expanding section 5. Inlet 6 of the device , the separation chamber 7 and the accumulator of foreign inclusions 8 are formed between the casing 1 of the pipeline and the Venturi nozzle 2, the inlet of which is connected to the inner surface of the casing 1 of the pipeline in places of contact, and the expanding portion is attached around the inner diameter of the pipeline, wherein the axis of nozzle 9 is inclined from 2 venturi axis of the conduit 1. The displacement of the axis of the Venturi nozzle 2 from the axis of the conduit 1 maximizes the entrance into the separation chamber 7 and contributes to more efficient removal of foreign bodies. For the proposed device is most typical Venturi nozzle made of sheet steel welded type. The optimal dimensional parameters of the Venturi nozzle:

- the diameter of the cylindrical section is d; - linear dimensions - h1; h2; h3;

- confuser angle - a2; - angle of the extended section - a3

are installed according to GOST8.586.3 and 4 Venturi nozzle "Technical requirements". Rigidity ribs 10 are installed between the pipeline 1 and the inlet part of the Venturi nozzle 2, and a separation grating 11 is made at the inlet of the separation chamber 11. The grating is made of metal ribs 12 located at an angle to the axis of the pipeline 1, blocking the direct passage into the separation chamber 7. For removal foreign inclusions to the accumulator of foreign inclusions 8 the nozzle 13 is connected. The accumulator of foreign inclusions 8 has a sufficient volume to provide periodic blowing through pipelines and regular blowing technology, according to the schedule bath unit is shut down.

The proposed device for cleaning steam or gas from foreign inclusions works as follows.

The principle of operation of the device is the use of inertial-centrifugal force when rotating the steam or gas flow, when solid particles are concentrated in the peripheral part of the pipeline, and the influence of inertial force on solid particles having a flow velocity at the moment of its contact with the input part of the device. When a two-phase flow moves at the turn of the pipeline 1 under the action of inertial-centrifugal forces, foreign inclusions move to its peripheral part and concentrate on its larger radius. Moving further, the two-phase flow is in contact with the inlet part 6 of the device, which covers the inner peripheral surface of the pipeline 1 and, in the peripheral surface of the pipeline most saturated with foreign inclusions, has a maximum value, while the flow velocity decreases sharply, the flow turns 90 ° and goes into the tapering part 3 venturi nozzles 2. However, the speed of foreign inclusions remains equal to the flow rate in the pipeline, and under the action of inertial force the particles continue to move and enter input part 6 of the device. Further, foreign inclusions, colliding with the separation lattice 11, are separated from the flow and, under the influence of inertial and gravitational influences, enter the separation chamber 7 and the accumulator 8.

Claims (1)

A device for cleaning steam or gas from foreign inclusions, including a pipeline inside which a Venturi nozzle is installed, a separation chamber and a foreign inclusions accumulator, characterized in that the separation chamber is formed between the pipeline and the Venturi nozzle, the inlet of which is connected to the inner surface of the pipeline at the contact point with the latter, and the expanding part - along the entire inner diameter of the pipe, stiffeners are welded on the inlet of the Venturi nozzle, while the diameter of the Venturi nozzle in the expanding hour and equal to the diameter of the pipeline, and a venturi nozzle axis is tilted from the axis of the pipeline, in addition, at the inlet into the separation chamber, the separation grating is installed.

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