RU2701428C2 - Pulsator - Google Patents

Abstract

FIELD: machine building.

SUBSTANCE: invention relates to power engineering, in particular to methods of flushing out circuit systems of nuclear steam generating units. Pulsator comprises tight housing and shaft rotating from motor-reducer 10. Housing is installed vertically and comprises cylindrical shell, bottom and cover, between which coaxially to axis of shell is mounted in bearing supports shaft, rotating in one direction from motor-reducer 10, arranged on outer side of cover. Two symmetrical blades are secured on the shaft. At the bottom there is a drain hole, to which drain pipeline 14 is connected. Between the inner walls of the shell and the outer edges of the blades there is a gap for sealing and adjustment of which along the perimeter of each blade detachable seals are fixed at an angle from the front plane of each blade to the rear one in the direction opposite to their rotation. On the outer side of the housing at equal distance along the perimeter and height there installed are four mutually perpendicular pipes 5 with flanges 6, which provide 4-fold change of direction of liquid movement in the flushed product per one revolution of the shaft.

EFFECT: invention is aimed at increasing efficiency of washing articles.

1 cl, 6 dwg

Description

The invention relates to the field of power engineering, in particular, to methods for flushing contour systems of nuclear steam generating units (APPU), and can be used for flushing pipelines and hydraulic systems of various transport objects, as well as in repairing power and transport systems.

The resource and operational reliability of equipment for various systems depends on the cleanliness of internal cavities, by thorough cleaning of which it is possible to prevent premature wear of critical elements and increase the duration of their trouble-free operation. That is why, the requirements for the purity of internal cavities and paths are mandatory for almost all systems and power plants, including nuclear ones. These requirements are set out in the relevant regulatory documents.

Modern washing methods can be divided into flow and intensive. The duration of flushing the systems by the flow method is quite large, and the approximate complexity of flushing the pipelines of hydraulic systems can be up to 40% of the total time spent on the manufacture and assembly of the entire unit. The power of the direct-flow washing stand electric drive in shipbuilding can reach more than 200 kW, therefore, the energy costs at the shipyard scale are very significant.

These disadvantages of the direct-wash method can be significantly reduced using the intensive washing method. For intensive flushing, in-line flushing stands include devices for intensifying flushing of pipelines and systems.

Several methods for intensive flushing of pipelines and systems are known. Of these methods, washing with the pulsating flow method and washing with the method of changing the direction of movement of the washing medium are most widely used.

The pulsating flow of the washing medium arises from the operation of the pulsator, which is connected to the direct-flow washing stand directly into the path or parallel to the path. When the pulsator is operating, a flow occurs with a pulsating flow rate and pressure of the washing medium.

The changed flow direction of the washing medium is created using a system of switches installed directly in the path of the direct-flow washing stand, and to change the direction of flow, it is necessary to turn off the electric drive of the stand to avoid water hammer.

A hydraulic pulsator according to SU 520 460 A is known, which provides a pulsating flow of a washing medium (working fluid), comprising a cylindrical body with radially arranged inlet and outlet working windows and a distribution window communicating with them, made on the outer cylindrical surface of the spool rotating inside the housing. The spool distribution window is made profiled in accordance with the shape of a given impulse of the washing medium, and in the case in the area of the outlet working window there is a device for changing the shape of this working window, made, for example, in the form of a set of profiled plates fixed in positions determined by the required pulse the shape of the window.

The disadvantages of this pulsator are:

- the washing medium during the operation of the pulsator moves only in one direction, therefore, accumulation of stagnant dirt zones in the washed cavities is possible, and, as a result, additional time is required for washing them:

- the predetermined shape of the pressure pulse of the washing medium is determined by the profile of the distribution window in the rotating spool and a set of profile plates in the area of the outlet working window of the housing, so the pulsator does not have the ability to control the pressure pulse in a wide range without stopping the cavity washing process itself.

A device is known that changes the direction of flow of the washing fluid in the washed product and the washing stand using a system of valves connected to a hydraulic bridge (J. "Shipbuilding". No. 6. 2011 (November-December)), p. 56.

The disadvantage of this device are:

- when washing cavities using this device, there is no impulse to change the pressure of the washing medium, which slows the separation of particles from the washed surfaces;

- before switching the direction of movement of the washing liquid to eliminate the phenomenon of water hammer, it is necessary to stop the washing process.

The closest in technical essence and the achieved result is a pulsator according to SU 335015 A, adopted as a prototype.

This pulsator contains a housing comprising successively connected communicating high-pressure chamber and a pulsation chamber, a shaft passing through the chambers, a rotating disk with windows mounted on a shaft in the high-pressure chamber, and a fixed disk located between the rotating disk and the pulsation chamber with windows identical to the windows of the rotating disk and located at the same distance from the axis of the shaft as the windows of the rotating disk. The windows of each of the disks have a different size and are located on the fixed disk along the radius, in order of increasing or decreasing their size, and on the rotating disk - in a spiral, in order to ensure that when the disk rotates, its windows are combined with windows of the same size of the fixed disk.

However, the prototype has the following disadvantages:

- when the pulsator is operating, the washing medium moves in only one direction and, as a result, accumulation of stagnant dirt zones in the washed cavities is possible, therefore, additional time is required for washing them;

- the predetermined shape of the pressure pulse of the washing medium is determined by the number and diameters of the openings of the windows that are located on the rotating and fixed disks, therefore the pulsator does not have the ability to control the pressure pulse in a wide range without stopping the washing process and replacing the rotating and fixed disks with a different number and diameter of holes .

The objective of the invention is to develop a high-performance reliable and relatively inexpensive pulsator with the ability to control periodic pulses of pressure of washing water in a wide range while changing the direction of flow only in the cavity of the washed product, without changing the direction of flow of the direct-flow washing stand.

The main technical result, due to which the task is ensured, is to increase the efficiency of washing products by:

- combining two methods of washing products - creating periodic pressure pulses and changing the direction of flow of the washing medium;

- regulation of the pressure pulse of the washing liquid in a wide range without stopping the drive of the once-through washing stand.

The technical result is obtained due to the fact that the pulsator contains a sealed housing and a shaft rotating from the gear motor, while the housing is mounted vertically and contains a cylindrical shell, as well as a bottom and a cover, between which the shaft is mounted coaxially to the axis of the shell in the bearing bearings rotating in one direction from the gear motor located on the outside of the cover, and two symmetrical blades are fixed on the shaft and at the bottom there is a drain hole to which the drain pipe is connected, p There is a gap between the inner walls of the shell and the outer edges of the blades, for sealing and adjustment of which removable seals are fixed along the perimeter of each blade at an angle of 15 ° from the front plane of each blade to the back in the direction opposite to their rotation.

In addition, 4 mutually perpendicular nozzles with flanges are installed on the outer side of the housing at an equal distance around the perimeter and height, providing for a 4-fold change in the direction of fluid movement in the washed product during one revolution of the shaft.

In the particular case, the shaft is mounted in the cover through angular contact rolling bearings and a sealing device, and at the bottom, through the sliding bearing, with the cavity of which the drain hole is combined.

The sealed housing, consisting of a cylindrical shell, bottom and cover, is a technological design, therefore, the manufacturing and repair technology of the pulsator is simplified.

Two symmetrically fixed blades on a vertical shaft rotating in one direction from the gear motor and 4 mutually perpendicular nozzles with flanges mounted on the outside at an equal distance on the housing provide a 4-fold change in the direction of fluid flow in a washed product in one revolution of the shaft.

The installation of removable seals on the blades at an angle of 15 ° from the front plane of each blade to the rear in the direction opposite to their rotation allows you to protect the lips of the seals from scoring and intense wear, thereby increasing the working life of the pulsator.

The vertical position of the shaft rotating from the gear motor allows it to be installed with the mating cover through angular contact rolling bearings and sealing devices (for example, by NPO Sfera from the Aes Seal EU distributor), and with the mating bottom through the sliding bearing, with the cavity of which the drain hole and the drain pipe are combined. Thus, the number of sealing devices is reduced by 2 times, the presence of which significantly complicates and increases the cost of the pulsator design. A decrease in the number of seals also contributes to an increase in the pulsator's motor resource.

As a result, the proposed group of inventions solves the problem of developing a high-performance reliable and inexpensive pulsator with the ability to control periodic pressure pulses of the washing water in a wide range, while changing the flow direction only in the cavity of the washed product without changing the flow direction of the direct-flow washing stand.

The invention is illustrated by the following graphic figures:

FIG. 1. General view of the pulsator.

FIG. 2. Top view

FIG. 3. Section AA. The pulsator section of the shaft seal on the cover.

FIG. 4. Section BB. The pulsator section along the shaft sliding bearing at the bottom.

FIG. 5. View B. Attaching the seal to the blade.

FIG. 6. The scheme of operation of the pulsator and its connection to a direct-flow washing stand and the product being washed.

A pulsator with the ability to control the pressure pulses of the washing water while changing the direction of flow only in the cavity of the washed product, without changing the direction of flow in the direct-flow washing stand consists of the following main parts.

The pulsator is made in the form of a sealed housing 1, consisting of a cylindrical shell 2, bottom 3, cover 4, nozzles 5 and flanges 6. On the cover 4 is placed vertically on angular contact bearings 7 shaft 8, connected by a coupling 9, with a gear motor 10 Between the shaft 8 and the cover 4, a sealing device 11 is installed that protects the angular contact rolling bearings 7 from leaks during rotation or stop of the shaft 8 in the housing 1 (Fig. 1-3).

At the bottom 3, a sliding bearing 12 is installed, into which the lower end of the shaft 8 is inserted. At the bottom 3, at the location of the sliding bearing 12, there is a drain hole 13, a drain pipe 14, a shut-off valve 15 (Figs. 1-4).

On the shaft 8, two blades 16 are symmetrically fixed, which are installed with a gap 17 around the perimeter of each blade between the inner walls of the sealed housing 1 and the outer edges of the blades 18. To seal the gap 17 around the perimeter of each blade 16, removable seals 19 are fixed (Fig. 4, 1, 2, 3).

The shell 2, bottom 3, cover 4 are interconnected through gaskets 20 and mounting pins 21 with nuts 22 into an airtight housing 1. Flanges 6 are welded to the nozzles 5, which are welded to the corresponding ends of the holes of the shell 2 (Fig. 1).

The pulsator is equipped with the necessary automation system, switching support and instrumentation (instrumentation). All controls are displayed on the control panel (not shown on graphic figures).

The pulsator operates as follows.

Before starting work, the pulsator 28 is connected to a direct-flow washing stand 23, consisting of a pump 24, a supply tank 25, a washing chamber 26, in which the washed product 27 is located.

Four nozzles 5 through the flanges 6 are connected to the washed product 27 in the washing chamber 26 and the washing stand 23 according to the following scheme (Fig.6):

- pulsator 28 - flushing stand 23 (with pump 24);

- pulsator 28 - flushed product 27 (with flushing chamber 26);

- pulsator 28 - flushing stand 23 (with a supply tank 25);

- pulsator 28 - flushed product 27 (with flushing chamber 26).

Then, the entire system consisting of a pulsator 28, a washing stand 23, and a washed article 27 together with the washing chamber 26 is filled with washing water.

After that, the operator using the automation system (CA) to control the operation of the pulsator 28 includes one of the programmed washing modes. The flushing mode is a certain combination of successive starts and stops, as well as changes in the speed of the gear motor 10, which leads to a change in the pressure and direction of the flow of flushing water in the flushed product 27 at predetermined intervals.

The motor gearbox 10, controlled by CA, rotates the shaft 8, with the blades 16 in only one direction (Fig. 5).

When the blades 16 rotate, the flow cross sections of the wash water flows continuously change in all nozzles 5 of the pulsator, therefore, there is a continuous change in pressure in these flows.

When the blades 16 turn from position I to position II → III (Fig. 6-a, 6-b) and then to position IV → V → VI (Fig. 6-c, 6-d), the direction of flow of water in the flushed product 27, that is, for 0.5 revolution of the blades 16, the direction of flow of water in the product 27 and the washing chamber 26 changes 2 times, and for 1 full revolution of the blades 16 the direction of flow changes 4 times.

To seal the gap 17 and eliminate leaking water leaks on the outer edge 18 to each blade 16, removable seals 19 are fixed (for example, fluoroplastic, Fig. 5).

The gear motor 10 consists of an induction motor assembled with the gear. The electric motor is equipped with a speed sensor and a frequency converter for the possibility of adjusting the number of revolutions of the output shaft of the gearbox using SA according to a specially developed program for washing the washed product 27.

The present invention provides for the creation of a reliable, relatively inexpensive pulsator, with the possibility of connecting to the systems of a direct-flow washing stand and a washed product, which significantly reduces the washing time of the product and saves energy costs by controlling the pulse of washing water in a wide range without stopping the drive of the washing stand and combining two methods washing products - creating periodic pressure pulses and changing the direction of the wash water flow.

The present invention allows the adaptation of the pulsator without affecting the infrastructure in the existing direct-flow washing stands.

Claims (2)

1. A pulsator comprising a sealed housing and a shaft rotating from a gear motor, characterized in that the housing is mounted vertically and contains a cylindrical shell, as well as a bottom and a cover, between which, coaxially to the axis of the shell, a shaft rotating in one direction from a gear motor located on the outside of the cover, two symmetrical blades are fixed on the shaft, at the bottom there is a drain hole to which a drain pipe is connected, and between the inner walls of the shell and the outer edges of there is a gap for sealing and adjusting which around the perimeter of each blade removable seals are fixed at an angle of 15 ° from the front plane of each blade to the rear in the direction opposite to their rotation, in addition, 4 are installed on the outside of the body at an equal distance around the perimeter and height mutually perpendicular to the nozzle with flanges, providing for one rotation of the shaft 4-fold change in the direction of fluid movement in the washed product. 2. The pulsator according to claim 1, characterized in that the shaft is mounted in the cover through angular contact rolling bearings and a sealing device, and at the bottom through a sliding bearing, with a cavity of which the drain hole is combined.

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