KR830000053B1 - Improved filter for purifying fluids containing ferromagnetic particles - Google Patents

Abstract

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Description

Improved filter for purifying fluids containing ferromagnetic particles

1 is an overall view of a filtration and unclogging circulator in which the cross-section is partially in the plane of the filter and is equipped with a first array of filters parallel to the primary pump in the primary circulation device of the reactor.

2 is a cross-sectional view in a vertical plane through an embodiment of the filter according to the present invention.

3 is a half sectional view taken along line A-A of FIG.

4 is a cross-sectional view in the vertical plane seen through the second arrangement of a filter embodiment according to the invention in which the primary circulation device of the reactor is cut off on its cold side and the purified water under the vessel lid is fed back.

The present invention relates to an improved filter for purifying a fluid comprising ferromagnetic particles and in particular for purifying a primary fluid in a reactor using pressurized water.

In reactors using pressurized water, pressurized water, which constitutes the primary fluid and contacts the fuel rods before being sent to the boiler feedwater, ie, to the steam generator for evaporating and heating the secondary fluid, is supplied to the reactor during circulating the reactor and the steam generator. It is charged with the iron oxide particles formed during long contact with any steel part of.

This prevents the amount of oxides in the primary fluid from becoming excessive and activates the particles after they have been deposited in the reactor core and subsequently deposited in the primary pipe, thus seriously affecting the contamination and activity of their surfaces. It is extremely important to remove the oxide particles with a filter.

Are particles trapped by the filter no longer circulating in the primary circulation, reducing the likelihood of contaminating operators and maintenance personnel? Therefore, personnel in charge may be next to the reactor unit for a new time without being overly investigated.

Of course, in order to continue to purify pressurized water, the purification of this primary fluid must take place during operation of the reactor.

However, the problem is that such filtration must be done in hot pressurized water.

To achieve this purification, it has been proposed to use an electromagnet filter consisting of a cylinder filled with beads of ferromagnetic material such as steel beads subjected to magnetization cycles so that the beads retain the ferromagnetic particles delivered by the primary fluid. .

To form a magnetic field capable of magnetizing a bead, this type of electromagnet filter, consisting of a coil surrounding the envelope in which the bead is located, is usually arranged parallel to the primary pump used for circulation of pressurized water.

In addition, the inside of the cylindrical envelope including the bead is connected to an unclogging circulation device separated from the primary fluid circulation device to periodically remove the oxide particles retained in the bead.

A portion of the primary fluid stream, usually a few percent of the fluid stream, is converted to a filter.

As such, it is necessary to continuously purify the primary fluid so that it does not interfere with the circulation of the fluid in the primary circulator and also does not lower (cool) the heat of the fluid, and also to remove this material from this filter regardless of the circulation. It is possible.

In the electromagnet filters used so far, the flow of fluid to be purified flows through one end of the filter and through the other end to be recycled to the primary circulation device through the steel bead bed.

Disadvantages of this type of filter are that, because the fluid circulates along a constant path, thin slices of oxide always tend to deposit on the same area of a set of steel beads, and the fluid circulation rate of the bead layer to aid filtration. It is difficult to ensure the maximum circulation rate of the fluid in the filter in order to limit the pressure and to at the same time enable very effective filtration.

Moreover, if it is desired to limit the circulation rate of the fluid in the filter and to increase the passage through a group of beads, there is a need to increase the size of this filter to an enormous volume and price thereof.

According to the present invention there is provided a filter for purifying a fluid comprising ferromagnetic particles, the filter having a cylindrical envelope having an inlet connected to the inlet pipe for the fluid to be purified and an outlet connected to the discharge pipe for the fluid to be purified; A current supply means for forming a ferromagnetic bead within the envelope and through which the fluid passes in use and a magnetic field that magnetizes the bead so that the bead can retain ferromagnetic particles carried by the fluid during use. A coil connected to and enclosing the cylindrical envelope, an unclogging circulator connected to the interior of the envelope, supporting the bead, mounted inside the envelope and coaxial with the envelope, Between the inside of the basket containing the steel bead and the envelope and the basket. A perforation is provided to connect the space so that the outlet is open therein, the perforation being in communication with the perforations formed in the area and the tip of the sidewall of the basket, and the basket in which the bead is located. In the region there is a solid wall mounted inside the basket and spaced inwardly from the sidewalls of the basket, with a deflector extending axially by a constant length and at one tip of the inlet. A central tubing connected to the other end and oriented along the axis of the strainer and installed in a bead layer in the center of the basket, ie radially opposed to the deflector. To place the interior of the tub in communication with the interior of the basket in the area of the web The deflector is opposed to the perforated area formed in the sidewall of the basket to prevent radial side perforation-fluid from passing directly from the central tubing to the space between the basket and the envelope along a unique radial path. And the region consists of said tubules which are located radially in opposition to said perforation of said central tube.

In the primary circulator of a reactor using pressurized water, for cutting and using in parallel with the primary pump or on the cold side of the primary circulator, an embodiment of the filter according to the invention is now only cited with reference to the accompanying drawings. One example will be described.

FIG. 1 shows a partial primary circuit of a nuclear reactor consisting of two large diameter pipes, 1,2 and a primary pump (not shown).

The two pipes 4 and 5 are installed in the shape cut out from the pipes 1 and 2, respectively, to extract a part of the pressurized water constituting the primary fluid, and allow the pressurized water to be recycled to the primary circulator.

Pipe 4 is an inlet pipe of pressurized water to be purified in filter 7 and pipe 5 is an outlet pipe of purified fluid flowing out of the filter.

The structure of the cylindrical filter, which will be described in greater detail with reference to FIG. 2, consists of an envelope, the majority of which is magnetized to ferromagnetic material, such as steel or beads, located inside the envelope. It is surrounded by a magnetic coil (8). The coil is composed of a cooling circulation device 9 and a yoke 10.

A mechanical safety filter 12 equipped with a power valve for separating the filter 7 from the pipe 2 and a magnetic and acoustic detector, the purpose of which is described in detail below, is provided. It is installed in the pipe 4.

Similarly, a valve 14 and a safety filter 15 are installed in the pipe 5.

In addition, the lower part of the filter 7 includes a pipe 16, a shell water storage tank 17, a pipe 18 for removing liquid effluent, a pipe 19 for removing a gas effluent, and an expansion storage tank. It is connected to an unclogging circulator composed of a circulator 20 for cooling it.

The power plant valve 21 and the safety filter 22 provided with the detector are installed in the pipe 16.

Valves 23, 24, 25 and 26 are also installed in the circulators for cooling the pipes 18 and 17 and the expansion reservoir tanks, respectively.

A vacuum pump 27 is also connected to the pipe 19 to release the gas effluent.

Referring to FIG. 2, it can be seen that the filter 7 is composed of a cylindrical envelope 30 covered with a hemispherical cover 31 at the top and an elliptical cover 32 at the bottom. .

Inlet orifice 34 for primary fluid connected to pipe 4, outlet orifice 35 for purified primary fluid connected to pipe 5, and inspection hatch 36. ) Is provided in the upper hemispherical cover 31.

The orifice 37 is in the lower elliptical base 32 so that it can be connected to the pipe 16 of the unclogging circulation device.

The filter is welded to a brace 40 which can be fixed.

Envelope 30 is made of nonmagnetic stainless steel and is designed to withstand the pressure and temperature of the primary fluid (eg 155 [bar] and 286 ° C.).

The elliptical base 32 of the envelope 30 of this filter is composed of radial projections 41 and 42 which form a fixing part of a basket 45 in which steel beads are located. This bead is made of ferrite chrome steel.

1 and 2 show the upper surface 43 of the bead charged body, which is a perforated bracing plate 46 lying on the support angles 41 and 42 at the bottom of the basket 45. Is put on.

The oval base 47 is also fixed to the lower plate 46 of the basket 45 and extends through it.

The plate 46 and the base 47 have a circular shape in the center part of which is inserted and guided into a hollow column 48 which is integrated into the elliptical base 32 of the envelope 30. There is an opening and is arranged perpendicularly and coaxially to the envelope 30 so that the orifice 37 opens inward of the column 48.

A perforation 49 is provided in the base of the column 48 such that the orifice 37 and the pipe 16 are in communication with the space region between the envelope 30 and the basket 45.

The basket 45 is composed of cylindrical side walls lying on the support angles 41 and 42 located on the outer surface of the plate 46. The upper plate 50 is fixed to the upper thick portion of the side wall of the basket 45, through which the perforation 51 extends.

The spacing between the basket 45 and the envelope 30 is maintained by a spacer 52 welded to the top of the cylindrical basket 45.

The filter 7 also consists of a central tube 55 coaxially with the envelope 30 and the basket 45 and an orifice 34 formed therein.

In the central tube 55, a side perforation is formed over the entire length of the tub, which is located opposite the deflector 56 fixed to the side wall of the basket 45. As shown in FIG.

The lower part of the center tube 55 is closed with a bearing pin 56 mounted on the top of the common column 48 for guiding and securing the center tube to the envelope 30.

As shown in FIG. 2 and FIG. 3, the deflecting device 57 is composed of a three-dimensional wall that is cylindrical in shape, constitutes a sector hanging at about 60 °, and has a basket with a radial spacer 58. It is fixed to the inner side wall of (45).

In this manner, the deflecting device 57 maintains a constant distance from the inner wall of the basket 45.

The three deflectors are provided at a constant distance from the inner wall of the basket 45, between which there is a cylindrical sector hanging at about 60 ° and this part is not equipped with a deflector.

As shown in FIG. 3, the side wall of the basket 45 is formed with perforations penetrating the outer wall of the sector 59. As shown in FIG.

Sector 59 is intersected by the envelope symmetry plane of the strainer (i.e., the plane including the strainer vertical axis of symmetry) through the far-end generatrix in contact with the cylindrical deflector 57, It abuts against the wall of the basket 45.

Sectors located between these sectors 59 and lying radially behind the deflector are each composed of three-dimensional walls which completely separate this basket in the space between the envelopes 30 of the basket.

In addition, the basket 45 has several perforations at the tip of the vertical sidewall, so that the interior of the basket is connected with the area between the basket and the envelope 30.

Perforations made in the basket and central tubing have a diameter such that they cannot penetrate the perforations even when the beads are slightly corroded. Furthermore, the perforations are arranged in a constant arrangement inside the grooves which are machined on the outer surface of the wall through which the perforations pass.

The operation of the filter described above will now be described.

A constant amount of primary fluid flow in the discharge pump is diverted from pipe 2 to pipe 4. This amount is on the order of 2% to 4% of the total amount of primary fluid shake in the pipe 2.

When the valve 11 is opened, the pressurized water constituting the primary fluid flows into the central tube 55 of the filter 7 through the orifice 34. This pressurized water passes through this central tubing 55 through a perforation in the tubing made at a constant height inside the bead layer that fills the basket surrounding the central tubing. As such, the pressurized water initially penetrates into the bead layer in the radial direction.

The magnetizing coil is supplied with direct current to operate continuously to maintain the level of the predetermined magnetic force of the bead.

The supply current required to magnetize this bead is normalized by determining the current that generates a magnetic field of 1,800 hertz when there are no beads in the basket.

Before passing through the filter, the fluid in contact with the magnetized beads leaves the ferromagnetic oxide particles contained in the bead layer.

In the initially tubular tubing 55, the waterway is such that the water contacts the deflector 57 or the three-dimensional sector of the wall of the basket 45 located between the area sectors 59.

As such, the water cannot leave the basket, and the waterway deflector or three-dimensional sector is in the horizontal, vertical, or along a complicated way until the water reaches the area between the deflector and the inner wall of the basket 45. Bends along the wall of the water, in which the water enters the space between the basket and the envelope 30 through a perforation behind the shifting device 57.

In addition, a portion of the water is formed at the lower and upper ends of the sidewalls of the basket 45 through perforations made in the cover 50 or the plate 60 and the cover 47, beyond the area occupied by the deflector. The basket 45 is left through the perforations 61 and 62. As such, water eventually reaches the area between the basket 45 and the envelope 30 or the top of the filter and is discharged through the orifice 35 and the discharge pipe 5 and recycled to the primary circulator.

As such, pressurized water is discharged through the orifice 35 and the pipe 5 to the top of the filter in all cases.

In all cases, the water just leaves the basket through a complex and relatively long road and passes through the filter in several directions. As such, the bead layer is fully used to purify the water.

The deflector is designed such that the rate of diffusion of the primary fluid through the bead layer does not exceed 50 cm / sec.

In the special case of a pressurized water reactor employing a filter as described above, the temperature and pressure of the primary circulator to be treated are 286 ° C. and 155 [bar], respectively. Therefore, the various elements of the filter are designed and designed to withstand this condition.

Under these operating conditions, the filter is designed to handle a maximum inflow of 255 liters of water per second.

After operating the filter for a period of time under constant operating conditions, it is necessary to perform a certain amount of unclogging to remove the coral particles that are retained in the beads. To do this, the filter 7 is separated from the primary circulator by locking the valves 11 and 14, where the filter is filled with water at 286 ° C. at 155 bar and the expansion reservoir tank is vacuum pump 27 ), Purge with air in the expansion reservoir, program the current change and reverse the polarity of the magnetization coil to remove magnetization of the bead charged body, and then open the valve 21 to open the filter to expand the reservoir It is possible to communicate with (17).

It is possible to expand the pressurized water in the strainer with one of the two valves 21 which allows the expansion reservoir to be separated from the strainer.

The installation and volume of the expansion reservoir in proportion to the filter ensures that once one expansion operation is completed, steam remains in the filter, and the water filled with the active effluent remains in the expansion reservoir, which cools the active liquid effluent and quickly depressurizes it. It is designed to be easy to make.

Therefore, at the moment the valve opens, expansion occurs, during which the beads in the filter are cleaned with an emulsion of water and water vapor formed by expanding the pressurized water, and when this is complete most of the water in the filter While entering the vessel, the filter is filled with water vapor with a pressure of 55 [bar] and a temperature after expansion of 270 ° C. At this time, when the valve 21 is closed, the expansion reservoir tank is separated from the filter, and when the valves 25 and 26 are opened, cooling of the expansion reservoir tank is started. At this time, the temperature of the expansion storage tank is dropped from 270 ℃ to 80 ℃.

At this time, when the valve 63 is opened, the filter is filled with water flowing from the unclogging circulator 60. The temperature of this unclog of water is 250 ° C. and the pressure in the filter after filling is 150 [bar].

In addition, when the pressure and temperature of the expansion water storage tank drops to an appropriate level, the valve 23 of the circulator for removing the liquid analogy and the valve 24 of the circulator for removing the gas effluent are opened, and the vacuum pump is opened. Running (27) causes the expansion reservoir to become empty.

At this time, the second expansion in the filter is executed by repeating the same operation as above, and the third expansion is started in the second expansion under the same conditions.

At the end of the unclogging operation, the filter is filled with 150 [bar] and 250 ° C. water by an unclogging circuit, and the bead charge is free of beads in the filter as determined by current-standardization for 1-2 minutes. When it forms a magnetic field of 3,200 [ersteds], the intensity is magnetized again by flowing 1,800 [adjusted to obtain a nominal magnetic field of Ersteds].

During the unclogging operation, the water in the strainer may be emptied by having a perforation 49 located at the base of the column 48 which is made integral with the envelope 30 of the strainer 7.

The safety filters 12, 15 and 22 described above can protect the installation from moving materials that may be accidentally contained in the primary fluid. Therefore, magnetic and acoustic detectors for indicating and recording the presence of such moving material in the primary fluid are provided with these safety filters at the inlet and outlet of the filter, on the circulator and the unclogging circulator for recycling the clarified fluid. Are combined.

Other types of protection, for example when the coil is heated, when the filter is not filled with water, when the separator valve is opened, when the pressure is too low for the filter, when the valve is opened. Protection devices are designed to separate the filter from the primary circulation in the event of unclogging of the device and a decrease in the supply of electricity to the coil.

Apart from the advantages presented in conventional devices, the device described above has a location of perforations in the basket containing the bead, and a central tubing that has a deflector and allows the primary fluid to initially obtain a radial path. Thus, it can be seen that the primary fluid can be purified much more effectively, with the fact that the passage of fluid through the bead layer can be slowed down and extended.

Moreover, compared to the previously known filter, this advantage is that it can be obtained without making the filter very large, and even has the advantage of reducing the dedicated capacity of the filter.

4 shows another embodiment of connecting the filtration circulator to the primary circulator. In this embodiment, the strainer 7 constitutes the cold side of this circulator and is connected to the tubing 67 of the vessel 64, by tapping on the site of the primary circulator pipe 66 ( It is integrated into the filtration circulator consisting of 65).

On the extension of the tapping 65, the filtration circulator consists of a pipe 68 which ends at the dip tube of the strainer 7 and two separate valves 70 and 71 fitted therein. Consists of.

The water leaves the strainer through pipe 69, passes through two insertion valves 72 and 73, one or two messages, which are not used but usually intended to be used as a mechanism to control a group of inhaled materials. Passage through (75) is recycled to the vessel via a spray nozzle such as (74).

A nozzle like 74 is connected to pipe 69 via seam 76 and drain circulator 77. A side pipe 78 is also provided, which is provided with two stop valves 79 and 80 to short-circuit the filter. There is a difference in input between the point on the cold side of the primary circulator connected to the spray tapping and the top of the vessel under the cover in which the spray nozzle is located so that water can be purified in the filtration circulator.

Tapping, which is usually used to inject pressure, is used with tapping 65. Using the flow of water through the spray nozzles at about 1% of the total inflow to cool the reactor core, the temperature of the vessel “dead” volume located under the lid is maintained quite moderately.

Moreover, one of the advantages of this unique arrangement of the circulating device is that it can cool down the “dead” volume under the vessel cover of the reactor as a device for recycling purified water.

Cooling by injection is necessary in any case, and it is possible to make cooling in a favorable state by recirculating purified water to the point on a container. Moreover, the injection of purified water under the cover can prevent the introduction of by-products of corrosion floating in the water at this point, and the inherent weakness of welding—that is, the activation of the area under the cover makes it difficult to operate the mechanisms controlling the welding. You can avoid losing. Increased flow rates can also be used to open the valve on the side of the strainer to wash out the “dead” volume under the cover.

The present invention is not limited to the examples described, but includes all modifications thereto. Therefore, if the direct passage of water to be purified from the central tube to the space between the filter's basket and the envelope can be fixed to the inner wall of the basket with radial displacement and blocked by various shapes, arrangements and deflectors, the deflector It is possible to change the shape and arrangement of the perforations of the basket including the beads.

Although two embodiments have been described in connecting the filtration circulator to the primary circulator, the connection parallel to the primary pump and the connection inserted between the cooling side and the lid of the vessel, the filter according to the invention is not a pump but a primary It can be installed in parallel with any member of the circulator, and a sufficient pressure difference is set for any member due to the circulation action of the coolant such as the steam generator. It is also possible to design the filtration circulator in such a way as to form a joint between the various bends of the furnace.

The filter according to the present invention can be combined with a device as described above, which is composed of an unclogging circulation device having an expansion reservoir, and also of any type of unclogging circulation device connected to the inside of the envelope of the filter. It can be combined with any device. Finally, while the apparatus for purifying the primary fluid of a reactor using pressurized water is of great value, the filter according to the invention can be applied to other applications, e.g., to boil water in a reactor using boiling water or to a boiler. It can be used to determine the water supply of any current thermal device that is constructed.

Claims (1)

A filter for purifying a fluid containing ferromagnetic particles, comprising: a cylindrical envelope having an inlet connected to the inlet pipe for the fluid to be purified and an outlet connected to the outlet pipe for the purified fluid, and within the envelope and in use And a cylindrical manbell connected to a current supply means to form a ferromagnetic bead through which the fluid flows through and a magnetic field that magnetizes the bead so that the bead can retain ferromagnetic particles carried by the fluid during use. A coil enclosing the loop, an unclosing device connected to the interior of the envelope, a cylindrical basket supporting the bead and mounted inside the envelope and coaxial with the envelope, ie the Between the interior of the basket containing steel beads and between the envelope and the basket In the basket, in the region of the basket in which the bead is located, a cylindrical basket provided with a perforation connecting the space so that the outlet is open therein, the perforation being provided in the region of the basket sidewall and the tip of the basket. A three-dimensional wall disposed inwardly and spaced inwardly from the sidewall of the basket, the redirecting mechanism extending over a constant length in the axial direction, connected to one leading end at the inlet and ending at the other leading end; And a central tube arranged in the bead layer in the center of the basket, ie in the region above the tub that is radially opposed to the deflecting mechanism. A side cloth in a radial direction to place the inside to be connected with the inside of the basket. In order to prevent fluid from passing directly from the central tube along the radial path into the space between the basket and the envelope, the deflecting mechanism is opposed to the perforated area formed in the sidewall of the basket. And a central tube having a region, the region of which is radially located opposite the perforation of the central tube, and the like. A filter for purifying a fluid comprising ferromagnetic particles.

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