JPS6012111A - Method and apparatus for backwashing electromagnetic filter - Google Patents

Abstract

PURPOSE:To facilitate the maintenance and control of an apparatus by re-utilizing obtained supernatant water as backwashing water, in a method for backwashing the high gradient electromagnetic filter in a high temp. and high pressure aqueous system, by precipitating and separating clad in waste backwashing water by the magnetic flocculation action of said filter. CONSTITUTION:Raw water A is passed through a matrix 2 from the space 4 of an electromagnetic filter 1 to remove clad therein while treated water is returned to a system from R. In performing backwashing, water A is returned through a bypass line 12 and allowed to remain in the filter 1. On the other hand, the water level of a precipitation separation tank 15 is adjusted to a height for submerging a distributor 15a. When a valve 13 is abruptly opened in this state, water in a space 5 is abruptly flowed down through the matrix 2 to peel off and remove adhered clad. In this case, flashed discharged water is diffused into and mixed with water in the tank 15 and steam therein is also condensed to receive a total amount water in the tank 1. In the next step, supernatant water from the tank 15 is used as backwashing water and plural times of backwashings are further performed.

Description

Detailed Description of the Invention - 10 Technical Field of the Invention The present invention relates to an electromagnetic filter for removing crud in high-temperature, high-pressure water systems in thermal power plants, nuclear power plants, etc. death,
The present invention relates to a method for backwashing a so-called high-gradient electromagnetic filter, which generates a high-gradient magnetic field, and an apparatus therefor.

2. Description of the Prior Art In general, an electromagnetic filter includes a matrix and an electromagnetic coil that magnetizes the matrix, and uses magnetic force to remove suspended particles (cladding) of ferromagnetic and weakly magnetic substances in a fluid.
A filtration process is carried out to separate and remove socks, but if crud accumulates in the matrix due to continued filtration and the differential pressure increases, or if the filtrate quality deteriorates due to a decline in filtration function, , the filtration must be interrupted and the matrix backwashed.

However, conventionally, the backwash waste liquid is sent directly to the waste liquid treatment equipment for treatment, which places a large burden on the waste liquid treatment equipment←land≠→4→, and it is necessary to increase the capacity of the treatment equipment. However, there were problems such as difficulty in operation and maintenance.

3. Purpose of the invention The present invention accurately solves the problems of the conventional system described above,
It is an object of the present invention to provide a backwashing method and a device therefor that can significantly reduce the amount of backwashing waste liquid discharged from an electromagnetic filter.

4. Structure of the invention - The present invention provides a method for backwashing a high-gradient electromagnetic filter equipped with an electromagnetic coil and a matrix that receives high-temperature and high-pressure water.
This is a method for backwashing an electromagnetic filter, which is characterized in that Cla-Rad□ in backwash wastewater is sedimented and separated by its magnetic coagulation, and the resulting supernatant water is reused as backwash water.

The present invention also provides an electromagnetic coil that receives high-temperature and high-pressure water.
In a backwashing device for a high-gradient electromagnetic filter equipped with an IJ sock, a flood drainage channel having a quick-opening valve is connected to the inflow side of the matrix, and the outflow side of the quick-opening valve is connected to the sedimentation separator. The electromagnetic filter backwashing is characterized in that the sedimentation separation device and the inflow side of the matrix are connected to each other by a return path having a pump, and the outflow side of the matrix is further connected to a pressurized gas supply path. It is a device.

5. Description of an Embodiment An embodiment of the present invention will be described based on FIG. A space 4 and a space 5 are partitioned. The water flow partition plate 3 is a perforated plate and serves to hold the matrix 2 and evenly distribute water flow. Further, an electromagnetic coil 6 is arranged around the outside of the matrix 2, and when a direct current flows through this electromagnetic coil 6, the matrix 2 is magnetized, and furthermore, the magnetic force is focused on the "sharp part" of the steel cool. Constructed to generate high gradients.

An inlet passage 8 for raw water A having an inflow valve 7 is connected to the space 4 on the inlet side of the matrix 2, and an outlet passage 10 for filtered water B equipped with an outflow valve 9 is connected to the space 5 on the outflow side. ,
Furthermore, the inlet channel 8 and the outlet channel 10 are directly connected by a bypass channel 12 having a bypass valve 11 .

On the other hand 1. A flash drainage channel 14 having a quick-opening valve 13 branches off from the inflow channel 8, and the end thereof is connected to a sedimentation separation tank 15 which also serves as a flash tank.

This sedimentation separation tank 15 is a sealable cylindrical container with an inverted conical bottom, and an exhaust passage 17 having an exhaust valve 16 at the top.
, an outflow path 19 for supernatant water E in which a plurality of outflow valves 18a to 18d are branched and arranged in multiple stages in the vertical direction on the side wall, and a discharge valve 2 at the bottom.
A discharge passage 21 for sedimentary clay water provided with 0 is connected to each of the drains 21. Further, above the central part of the sedimentation separation tank 15, a cylindrical collision plate 15b is fixedly arranged to surround the distributor 15a1 made of a perforated pipe or the like, and directly above the collision plate 15b is placed to prevent entrainment of droplets. A baffle plate 15c is provided for this purpose. and,
The outflow path 19 is connected to a storage tank 22, and the bottom of the storage tank n is communicated with the space 4 of the electromagnetic filter 1 through a return path 25 in which a pump 26 and a return valve 24 are interposed.

Note that the discharge path 21 is connected to a waste liquid treatment device (not shown).

Further, a degassing passage 27 having a degassing valve 26 and a gas supply passage 29 having a supply valve portion for pressurized gas C are connected to the space 5 of the electromagnetic filter 1, and the end of the degassing passage υ It is connected near the top of the separation tank 15.

Next, FIG. 2 shows another embodiment of the present invention, in which the end of the flash drainage channel 14 is connected to a flash tank 31, and the waste liquid in the flash tank 31 is discharged to the sedimentation separation tank 15. The supernatant water E is configured to flow into the storage tank n after being treated in step '.

That is, the flash tank 31 has an exhaust valve 1 at the top.
A discharge passage 17' having a diameter of 6' is connected to a discharge passage 66 for drain water having a discharge valve 32 at the middle part of the side wall, and the end of the discharge passage 36 is opened at the upper part of the sedimentation separation tank 15'. There is. Also connected to the bottom of the flash tank 31 are a discharge passage 33' having a discharge valve 62' and a discharge passage 65 having a discharge valve 34.
5, and the discharge path 65 is connected to a waste liquid treatment device (not shown).

Furthermore, a supply line 36 for water supply F is connected to the storage tank n, and the bottom of the supply line 36 is connected to the pump 23 and the return lines g, 25 and 3.
8 to the lower part of the flash tank 61, the space 4 of the electromagnetic filter 1, and the raw water storage tank 39, respectively. In addition, in Fig. 2, 401, 41, 42 and 43 are return valves, the shrine is a pump for returning the water held in the electromagnetic filter 1 to the raw water storage tank 39, and the kudzu is a perforated pipe, etc. is a distributed distributor.

The sedimentation separation tank 15' is a circular sedimentation tank made of concrete, and cover plates 15d and 15e are provided above the water surface and overflow device 15'', respectively, to prevent dust from entering. Furthermore, if a center well is installed near the water surface in the tank, a scraper for the sedimented crud water is placed at the bottom of the tank, and a sedimentation promoting member with an inclined plate is submerged below the water surface, sedimentation separation can be carried out more effectively. can.

Therefore, in the example shown in FIG. 1, the filtration process by the electromagnetic filter 1 is performed by opening the inflow valve 7 and the outflow valve 9, closing the quick-open valve 13 and the bypass valve 11, and closing the electromagnetic coil 6-
is energized. That is, raw water A (high-temperature, high-pressure water) to be treated enters the space 4 of the electromagnetic filter 1 via the inlet valve 7, and then passes through the matrix 2, during which 2 ml of water is removed, and the excess water B flows into the space 5. From there, it returns to the system via the outflow valve 9.

If this filtration process continues, will crud accumulate in the matrix 2 and the differential pressure will increase, or will the filtration function decline? Since the quality of the filtered ice water will deteriorate, the filter will be detected, the filtration will be interrupted, and the process will proceed to the backwashing process.

When entering this backwashing process, first open the bypass valve 11, close the outflow valve 9, then close the inflow valve 7, and close the electromagnetic coil 6.
energization is stopped. As a result, the high-temperature, high-pressure water is bypassed through the bypass path 12, and the high-temperature, high-pressure water is retained inside the electromagnetic filter 1 as it is. □ On the other hand, for the sedimentation separation tank 15, the exhaust valve 16 is opened and the outflow valve 18a is opened in advance to set the water level in the tank to a level where the distributor 15a is submerged.

Quick-open valve 13 installed in flush drain 14 in black state
When the electromagnetic filter 1 is suddenly opened, the high-temperature, high-pressure water in the electromagnetic filter 1 undergoes a rapid depressurization and a portion of it evaporates and expands in volume, causing the water in the space 5 to rapidly flow down inside the IJ sock. The shearing force causes the crud attached to the steel wool to be peeled off and removed.

In this case, the flush drainage is done by distributor 15 &
The water vapor is diffused and mixed into the water stored in the sedimentation separation tank 15, and the water vapor in the flash drainage is also condensed, and the entire amount is received in the sedimentation separation tank 15.

However, in general, it is difficult to achieve a sufficient backwashing effect with the above-mentioned one-time operation, so the backwashing operation is performed multiple times using the supernatant water from the sedimentation separation tank 15 as backwash water in the following manner.

That is, after exciting the electromagnetic coil 6 again, the pump 26
is activated, the return valve 24 is opened, and the supernatant water stored in the storage tank n, which is at room temperature, is returned to the electromagnetic filter 1, and a predetermined amount of filtered water is stored in the space 5. Next, the electromagnetic coil 6 is demagnetized and the supply valve 28 is opened to supply pressurized air.

A pressurized gas C such as pressurized nitrogen is supplied above the space 5 to pressurize it to a predetermined pressure. Then, when the quick-opening valve 13 is suddenly opened, the filtered water passes through the one-atmosphere matrix 2, and the crud is removed.

After washing in this way, perform backwashing with filtered supernatant water for 2 to 5 minutes.
After repeating the process several times, at the end of the backwashing process, the exhaust valve 16 is left open and the supernatant water filtered by the electromagnetic filter 1 is filled into the space 5 and the flow path including the degassing path 27 shown by the thick solid line in Figure 1. to degas. In this case, the gas in the flow path connecting the outflow valve 9 and the supply valve section can be degassed by opening cocks provided close to these valves. The gas in the degassing path 27 can be exhausted from the exhaust valve 17, but completion of degassing can be confirmed by opening a cock provided at the end of the degassing path 27. Although we will have to return to the original filtration step, since the deaeration operation is performed as described above, there is no need to worry about air getting mixed into the filtered water.

In this way, high-temperature backwash wastewater first flows into the sedimentation separation tank 15, and then backwash wastewater at approximately room temperature flows into the sedimentation separation tank 15. Even if the backwash wastewater is at a high temperature, the water in the sedimentation separation tank 15 Since the water is mixed with the water, it is cooled very effectively and in a short time, and therefore there is no concern that thermal stress will occur on the tank wall. Incidentally, since the second and subsequent backwash wastewater #1 is trapped at room temperature, it goes without saying that there is no problem of the above-mentioned thermal stress.

Since the sedimentation separation tank 15 is provided with a collision plate 15b that surrounds the distributor 15a, even if the distributor 15m is above the water surface, high-temperature backwash wastewater will not be sprayed directly toward the tank wall. This also prevents troubles such as the water in the tank being disturbed and interfering with sedimentation and separation of the crud.Furthermore, the inflowing backwash wastewater is distributed evenly and radially within the tank. (Distributor tSa also causes such distribution effect).

Therefore, while the backwashing wastewater in the sedimentation separation tank 15 is allowed to stand still for a suitable period of time, the crud in the wastewater naturally aggregates because it is magnetic, and the aggregates have a flocculating effect. As a result, sedimentation and separation of the crud is effectively carried out, and the sedimented crud water settles at the bottom of the cypress.

The supernatant water E obtained in this way is allowed to flow quietly by opening appropriate outflow valves 18 and ~18d to prevent precipitated crud from being mixed in, and is stored in the storage tank η, while the settled crud water is discharged. It is transferred to the waste liquid treatment device via line 21.

Next, in the second example, the filtration step is carried out in exactly the same manner as in the example shown in FIG. 1, but the backwashing step is performed as follows.
will be implemented.

That is, - Confirm in advance that the distributor 45 in the flash tank 51 is submerged in water (if not submerged in water, supply the supernatant water in the storage tank n). Next, in the same manner as in the example shown in FIG. 1, backwashing is first performed using filtered water of the raw water A, and then backwashing is performed several times using filtered water stored in the storage tank 22. When the backwash process' is completed, the discharge valve 52 is opened and the waste water in the flash tank 61 is drained into the sedimentation separation tank 15.
', and the crud is separated by sedimentation. Therefore, the distributor shaft is normally under water at all times, but if desired, the discharge valve 62' may be opened to drain the entire amount of waste water from the flash tank 31 to the sedimentation separation tank 15'. Alternatively, only the waste water at the bottom of the di-rush tank 61 may be directly transferred to the waste liquid treatment device.

・In this example, if you do not want to discharge the raw water A out of the electromagnetic filter system, or if the amount of supernatant water in the storage tank n exceeds the amount required for backwashing, some of the supernatant water will be removed. The raw water and filtered water in the electromagnetic filter 1 can also be returned to the raw water storage tank 39 by the pump 23 and the shrine or by the pump.

6. Functions and Effects of the Invention As described above, according to the present invention, the amount of electromagnetic filter backwash waste liquid discharged outside the system can be significantly reduced, and therefore the capacity of the backwash waste liquid treatment device can be small. Moreover, the temperature of the supernatant water returned and reused for backwashing is approximately room temperature, so the backwashing process can be carried out much more safely and easily. Since this is carried out based on the coagulation effect of magnetism, there is no need to add a coagulant, and the structure of the sedimentation separator is simple, making it easy to maintain and manage.

[Brief explanation of the drawing]

FIG. 1 is a flow sheet of an embodiment of the device of the present invention, #I2
The cause is sheet 7a of another example. M... Raw water, B... Filtered water, C... Pressurized gas, D
... Sedimented cladding water, E ... Supernatant water, F ... Water supply, 1 ... Electromagnetic filter, 2 ... Matrix, 3.
...Water partition, 4.5... Space, 6... Electromagnetic coil, 7... Inflow valve, 8... Inflow path, ? , 18a-18
d river outflow valve, 10, 19...outflow path, 11...bypass valve, 12...bypass path, 13...quick opening valve,
14... Flash drainage channel, 15, 15'... Sedimentation separation tank, 15'... Overflow gutter, 15a, 45... Distributor, 15b... Collision plate, 15cm baffle plate , 15d, 15e...cover plate, 16, 16'...
Exhaust valve, 17, 17'...exhaust path, 20°32,
52', &4...Discharge valve, 2, 55, 55'
, &5...Discharge path, 22...Storage tank, 23, 44
... Pump, 24, 40 ~ weak ... Return valve, 25
, 57 , 313... Return path, 26... Deaeration valve, υ
...Degassing path, 28... Supply valve, 29... Gas supply path, 51... Flash tank, Shame... Supply path, 3
9...Raw water storage tank. Patent applicant: Patent attorney representing Ebara Infilco Co., Ltd.
1,000 1) Twisting Takao Maruyama

Claims (1)

[Claims] 1. A method for backwashing a high-gradient electromagnetic filter equipped with an electromagnetic coil and a matrix that receives high-temperature and high-pressure water, in which crud in backwash wastewater is separated by sedimentation by its magnetic coagulation. A method for backwashing an electromagnetic filter, characterized in that the obtained supernatant water is reused as backwash water. 2. In a backwashing device for a high-gradient electromagnetic filter equipped with an electromagnetic coil and a matrix that handle high-temperature, high-pressure water, a flash flow channel having a quick-opening valve is connected to the inflow side of the matrix, and the quick-opening valve is connected to the inflow side of the matrix. The outflow side and the sedimentation separation device are communicated, and the sedimentation separation device and the IJ Fuchs inflow side are connected to a return path having a pump, and a pressurized gas supply path is further connected to the outflow side of the matrix. It is characterized by the fact that Backwashing device for electromagnetic filters. 3. The backwashing device according to claim 2, further comprising a storage tank for storing supernatant water produced by the sedimentation separation device on the suction side of the pump provided in the return path. 4.: The sedimentation separation device is a sealable cylindrical container having an inverted conical bottom directly communicating with the outflow side of the quick-opening valve, with an exhaust valve at the top and a supernatant water outflow on the side wall. valve,
4. The backwashing device according to claim 3, further comprising a discharge valve for settled crud water at the bottom, and a distributing member and an impingement member for inflowing fludge water and wastewater inside, respectively. 5. The sedimentation separator is a circular settling tank made of concrete and equipped with a cover plate above the water surface, which is indirectly connected to the outflow side of the quick-opening valve; Between,
4. The backwashing device according to claim 3, further comprising a sealable flush tank having an exhaust valve at the top and a fludge waste water distribution/spouting member inside communicating with the quick-opening valve. 6. The backwashing device according to claim 4, wherein the outflow side of the matrix and the upper part of the sedimentation separation device are connected by a degassing path having a valve. I. The backwashing device according to claim 5, wherein the outflow side of the matrix and the upper part of the flash tank are connected to a degassing path having a valve. 8. Claim 6, wherein the inflow side of the matrix and a storage device for high-temperature, high-pressure water to be treated are connected by a pipe line having a pump, so that the water in the electromagnetic filter can be returned to the storage device. The backwashing device according to item 7 or item 7.