JPS6344005B2 - - Google Patents

Description

[Detailed Description of the Invention] 1. 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. This 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 Generally, an electromagnetic filter includes a matrix and an electromagnetic coil that magnetizes the matrix, and uses magnetic force to capture suspended particles (cruds) of ferromagnetic and weakly magnetic substances in the matrix and separate and remove them. However, if crud accumulates in the matrix and the differential pressure increases due to continued overflow, or if the overwater quality deteriorates due to decreased overfunction, the overflow is interrupted and the matrix is removed. Must be backwashed.

However, conventionally, backwash waste liquid is sent directly to the waste liquid treatment equipment for treatment, which places a large burden on this waste liquid treatment equipment, requiring a large capacity of the treatment equipment, and increasing operational efficiency.
There were problems such as maintenance and management being difficult.

3. Purpose of the Invention The purpose of the present invention is to provide a backwashing method and a device therefor, which can accurately solve the problems of the above-mentioned conventional system and significantly reduce the amount of backwash waste liquid discharged from electromagnetic filters. That is.

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

The present invention also provides a backwashing device for a high-gradient electromagnetic filter equipped with an electromagnetic coil and a matrix for passing high-temperature, high-pressure water, in which a flush drain 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 sedimentation separation device is connected to the outflow side of the matrix, and the sedimentation separation device and the inflow side of the matrix are connected by a return path having a pump, and further a pressurized gas supply path is connected to the outflow side of the matrix. This is an electromagnetic filter backwashing device characterized by:

5 Description of Embodiments An embodiment of the present invention will be described based on FIG. space 4 and space 5 respectively
are divided into sections. The water flow partition plate 3 is a perforated plate that holds the matrix 2 and serves to uniformly distribute water flow. Further, an electromagnetic coil 6 is arranged outside the matrix 2 to surround it, and when a direct current flows through the electromagnetic coil 6, the matrix 2 is magnetized, and the magnetic force is concentrated on the sharp portion of the steel wool, creating a high gradient. configured to occur.

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

On the other hand, a flash drain channel 14 having a quick-open 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, an exhaust passage 17 having an exhaust valve 16 at the top, and a plurality of outflow valves 18a to 18 on the side wall.
8d is connected to an outflow path 19 for supernatant water E which is branched in multiple stages in the vertical direction, and an outflow path 21 for sedimented cladding water D which is provided with a discharge valve 20 at the bottom. Furthermore, above the central part of the sedimentation separation tank 15, a distributor 15a composed of a perforated tube, etc., and a cylindrical collision plate 15b are fixedly arranged to surround this, and directly above the collision plate 15b are A baffle plate 15c is provided to prevent entrainment. The outflow path 19 is connected to the storage tank 22.
The bottom of the storage tank 22 is connected to the space 4 of the electromagnetic filter 1 through a return path 25 in which a pump 23 and a return valve 24 are interposed. Note that the discharge path 21 is a waste liquid treatment device (not shown).
It is connected to the.

Furthermore, a degassing valve 2 is provided in the space 5 of the electromagnetic filter 1.
6 and a supply valve 2 for pressurized gas C.
8 is connected thereto, and the end of the deaeration path 27 is connected to the vicinity of the top of the settling tank 15.

Next, FIG. 2 shows another embodiment of the present invention, in which the end of the flush drainage channel 14 is connected to a flush tank 31, and the waste liquid in this flush tank 31 is separated by sedimentation. The supernatant water E is configured to flow into the storage tank 22 after being treated in the tank 15'.

That is, the flush tank 31 has an exhaust passage 17' having an exhaust valve 16' at the top, and an exhaust passage 33 for flush drainage having an exhaust valve 32 at the middle part of the side wall.
are connected to each other, and the ends of the discharge passages 33 are opened at the upper part of the settling tank 15'. Further, a discharge passage 33' having a discharge valve 32' and a discharge passage 35 having a discharge valve 34 are connected to the bottom of the flush tank 31.
The discharge path 35 is connected to a waste liquid treatment device (not shown).

Further, the storage tank 22 has a supply path 36 for water supply F.
are connected, and the bottom thereof communicates with the lower part of the flush tank 31, the space 4 of the electromagnetic filter 1, and the raw water storage tank 39 via the pump 23 and return passages 37, 25, and 38, respectively. In addition, the second
In the figure, 40, 41, 42, and 43 are return valves, and 44 is a raw water storage tank 3 for water held in the electromagnetic filter 1.
9, and 45 is a distributor made of a perforated pipe or the like.

The sedimentation separation tank 15' is a circular sedimentation tank made of concrete, and the area above the water surface and the overflow gutter 15''
are provided with 15d and 15e, respectively, to prevent dust from entering. Sedimentation separation can be carried out more effectively by providing a centawell near the water surface in the tank, a scraper for the sedimented crud water at the bottom of the tank, and a sedimentation promotion member with an inclined plate submerged below the water surface.

Therefore, in the example shown in FIG. 1, the overflow by the electromagnetic filter 1 opens the inflow valve 7 and the outflow valve 9,
The quick opening valve 13 and the bypass valve 11 are closed, and 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 through the inlet valve 7, and then the crud is removed while passing through the matrix 2, and the excess water B passes from the space 5 to the outflow valve 9. Return to the system via .

As this over-processing continues, crud will accumulate in the matrix 2 and the differential pressure will increase, or over-water quality will deteriorate due to over-functioning.
When these are detected, the filtration is interrupted and the process moves on to the backwashing process.

When entering this backwashing process, first bypass valve 1
1 is opened, the outflow valve 9 is closed, and then the inflow valve 7 is closed to stop the energization of the electromagnetic coil 6. As a result, the high-temperature, high-pressure water is bypassed from 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, regarding the sedimentation separation tank 15, the exhaust valve 16 is opened and only the outflow valve 18a is opened in advance, so that the water level in the tank is set to a level at which the distributor 15a is submerged.

When the quick-opening valve 13 provided in the flash drain 14 is suddenly opened in such a state, the high-temperature, high-pressure water in the electromagnetic filter 1 will be partially evaporated due to the sudden pressure reduction and its volume will expand. Water rapidly flows down inside the matrix 2, and the shearing force of the water causes the crud adhering to the steel wool to be peeled off and removed. In this case, the flash wastewater is dispersed from the distributor 15a into the water stored in the sedimentation separation tank 15 and mixed, 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, the backwashing effect is not sufficient with the above-mentioned one operation, so the supernatant water from the sedimentation separation tank 15 is used as backwash water and the backwash operation is performed multiple times in the following manner.

That is, after energizing the electromagnetic coil 6 again, the pump 23 is operated, and the return valve 24 is opened to drain the storage tank 2.
The supernatant water at approximately room temperature stored in 2 is returned to the electromagnetic filter 1, and excess water is stored in a predetermined amount of space 5.
Next, the electromagnetic coil 6 is demagnetized, the supply valve 28 is opened, and a pressurized gas C such as pressurized air or 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 excess water passes through the matrix 2 at once, and the crud is removed.

After repeating the backwashing operation by supernatant water in this manner 2 to 5 times, at the end of the backwashing process, the supernatant water is supernatant in the space 5 and into the space 5 with the electromagnetic filter 1 open while the exhaust valve 16 is left open. The flow path including the deaeration path 27, shown by the solid line, is filled and degassed. In this case, the gas in the flow path connecting the outflow valve 9 and the supply valve 28 can be degassed by opening a socket provided close to these valves. Deaeration path 2
The gas in the chamber 7 can be exhausted from the exhaust valve 17, and the completion of the exhaust can be confirmed by opening the stop provided at the end of the exhaust passage 27. In this way, the process returns to the regular overflow process, but since the deaeration operation is performed as described above, there is no fear that air or the like will get mixed into the overwater.

In this way, high-temperature backwash wastewater first flows into the sedimentation separation tank 15, and then backwash wastewater at approximately room temperature flows, but 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 very effectively cooled in a short time, and there is no fear of thermal stress occurring on the tank walls. Incidentally, since the backwashing water from the second and subsequent times is at approximately room temperature, it goes without saying that there is no problem of the above-mentioned thermal stress.

A distributor 15 is installed in the sedimentation separation tank 15.
Since the collision plate 15b surrounding the distributor 15a is provided, even if the distributor 15a is above the water surface, high-temperature backwash wastewater will not be ejected directly toward the tank wall, and the water in the tank will not be disturbed. It also prevents troubles that would interfere with sedimentation and separation of the crud.
Furthermore, an effect can be obtained in which the inflowing backwash wastewater is evenly distributed almost radially within the tank (this distribution effect also occurs due to the distributor 15a).

Therefore, while the backwash 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 flocculation action is promoted by the aggregates. As a result, the sedimentation and separation of the crud is effectively carried out, and the sedimented crud water D settles at the bottom of the tank.

The supernatant water E thus obtained flows through the outflow valves 18a to 18.
d is opened, the water is allowed to overflow gently so that the precipitated crud does not get mixed in, and is stored in the storage tank 22, while the precipitated crud water D is transferred to the waste liquid treatment device via the discharge path 21.

Next, in the example shown in FIG. 2, the overflow process is carried out in exactly the same manner as in the example shown in FIG. 1, but the backwashing process is carried out as follows.

That is, it is confirmed in advance that the distributor 45 in the flash tank 31 is submerged in water (if not submerged in water, the supernatant water in the storage tank 22 is supplied). Next, in the same manner as in the example shown in FIG. 1, backwashing is first performed by overflowing the raw water A, and then backwashing is performed multiple times using overflowing water stored in the storage tank 22. When the backwashing process is completed, the discharge valve 23 is opened and the waste water in the flash tank 31 is drained into the sedimentation separation tank 15'.
Drain the water and separate the crud by sedimentation. Therefore,
The distributor 45 is normally located below the water surface, but if desired, the discharge valve 32' may be opened to drain the entire amount of waste water from the flash tank 31 to the sedimentation separation tank 15'.
Alternatively, the discharge valve 34 may be opened and only the waste water at the bottom of the flash tank 31 may be directly transferred to the waste liquid treatment device.

In this embodiment, if it is not desired to discharge the raw water A out of the electromagnetic filter system, or if the amount of supernatant water in the storage tank 22 exceeds the amount required for backwashing, a portion of the supernatant water is Alternatively, the raw water and excess water in the electromagnetic filter 1 can be returned to the raw water storage tank 39 by the pumps 23 and 44 or by the pump 44, respectively.

6. Functions and Effects of the Invention As described above, according to the present invention, the amount of electromagnetic filter backwash waste liquid discharged to the outside of the system can be significantly reduced.
Therefore, the capacity of the backwash waste liquid processing equipment can be small, and the temperature of the supernatant water returned and reused for backwashing is almost room temperature, making the backwashing process safer and easier. Sedimentation separation of crud is carried out based on the flocculating effect of the crud's magnetism, so there is no need to add a flocculant, and the sedimentation separation equipment has a simple structure and is easy to maintain. It brings about the effect of

[Brief explanation of drawings]

FIG. 1 is a flow sheet of one embodiment of the apparatus of the present invention, and FIG. 2 is a flow sheet of another embodiment. A... Raw water, B... Overwater, C... Pressurized gas,
D...Sedimented cladding water, E...Supernatant water, F...Water supply, 1...Electromagnetic filter, 2...Matrix,
3... Water flow partition plate, 4, 5... Space, 6... Electromagnetic coil, 7... Inflow valve, 8... Inflow path, 9, 18a
~18d... Outflow valve, 10, 19... Outflow path, 1
1... Bypass valve, 12... Bypass path, 13...
...Quick opening valve, 14...Flats drain, 15,1
5'... Sedimentation separation tank, 15''... Overflow gutter, 15a,
45... Distributor, 15b... Collision plate, 15c... Baffle plate, 15d, 15e... Lid plate, 16, 16'... Exhaust valve, 17, 17'... Exhaust path, 20, 32, 32 ', 34...Discharge valve, 2
1, 33, 33', 35...Discharge path, 22...Storage tank, 23, 44...Pump, 24, 40-43
... Return valve, 25, 37, 38 ... Return path, 26
... Degassing valve, 27... Degassing path, 28... Supply valve,
29... Gas supply path, 31... Flash tank, 36... Supply path, 39... Raw water storage tank.

Claims (1)

[Claims] 1. In a method for backwashing a high-gradient electromagnetic filter equipped with an electromagnetic coil and matrix that passes high-temperature, high-pressure water, the crud in the backwash wastewater is sedimented and separated by the action of its magnetic coagulation. A method for backwashing an electromagnetic filter characterized by reusing clear water as backwash water. 2. In a backwashing device for a high-gradient electromagnetic filter equipped with an electromagnetic coil and a matrix that passes high-temperature, high-pressure water, a flush drain having a quick-opening valve is connected to the inflow side of the matrix, and the outlet side of the quick-opening valve and An electromagnetic device characterized in that a sedimentation separation device is communicated with the sedimentation separation device, and the sedimentation separation device and the inflow side of the matrix are connected by a return path having a pump, and further a pressurized gas supply path is connected to the outflow side of the matrix. Filter backwashing device. 3 On the suction side of the pump provided in the return path,
The backwashing device according to claim 2, further comprising a storage tank for supernatant water produced by the sedimentation separation device. 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, an exhaust valve at the top, and a supernatant water outflow valve at the side wall; 4. The backwashing device according to claim 3, further comprising a discharge valve for sedimented clutter water at the bottom, and a distribution spouting member and a collision member for inflowing flush wastewater inside. 5. There is a circular sedimentation basin made of concrete with a cover plate above the water surface, in which the sedimentation separator is indirectly connected to the outflow side of the quick-opening valve, and between the circular settling basin and the quick-opening valve, there is a 4. The backwashing device according to claim 3, further comprising a sealable flush tank having an exhaust valve at the top thereof and a flush water distribution/spouting member inside thereof 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. 7. The backwashing device according to claim 5, wherein the outflow side of the matrix and the upper part of the flash tank are connected by a degassing path having a valve. 8. Claim 6 or 8, wherein the inflow side of the matrix and a storage device for high-temperature, high-pressure water to be passed through 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.