JPS5916517A - Treatment by of electro magnetic filter - Google Patents

Abstract

PURPOSE:To improve the removing rate of suspended iron, by passing water in parallel or in series through the layers of magnetic packing materials arranged in plural lines in accordance with the quantity of condensed water. CONSTITUTION:When condensed water at the time of normal running is treated, the condensed water is parallelly passed through the layers A', B' of magnetic packing materials from a flow-in mother pipe 1 and a connecting pipe 5 by opening valves 12, 14 and closing a valve 3, and the treated water is gathered by a water gathering mechanism 10 and is passed through desalting towers A-D of the condensed water placed at the rear stage from a water gathering pipe 11. When the condensed water at the time of starting or stopping is treated, the water is passed through the layers A', B' in series from the pipe 1 by opening the valve 13 and closing the valves 12, 14, and the treated water is passed through the desalting towers A-D placed at the rear stage from a flow-out mother pipe 4.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for treating boiler condensate in a power plant using an electromagnetic filter.

By simply changing the water flow path, we can efficiently handle condensate during normal power plant operation and condensate during startup or shutdown, where the flow rate is lower than normal condensate and the amount of suspended iron increases. for the purpose of processing.

Electromagnetic filters remove magnetic suspended matter in the water being treated.

It is removed by adsorption to a layer of magnetic packing material packed inside a p-filtration tower, and is used for a variety of purposes, but in recent years it has come to be used to treat boiler condensate at power plants. It's here. That is, the electromagnetic filter is installed at the front stage of the condensate demineralization tower, and the suspension method in the condensate is removed in advance, thereby reducing the load on the condensate demineralization tower at the subsequent stage.

On the other hand, in recent years, with the shift to base load nuclear power plants, regular thermal power plants have experienced frequent boiler outages, such as weekend outages and overnight outages, and as a result, the properties of boiler condensate have become thicker [1] It has started to change. For example, the suspension method in condensate when the boiler is operating normally is 5 to 0 ppb.
However, when the boiler is started or stopped, the suspension method in condensate reaches 500 to 1,000ppb, which is about 50 to 100 times higher, and the flow rate of condensate decreases to about % compared to normal times. do.

The reason why the amount of suspension in condensate increases when the boiler is started or stopped is because the iron oxide adhering to the water pipes is peeled off all at once due to rapid changes in flow rate. This is thought to be due to contamination in condensate.

By the way, the conventional electromagnetic filter processing method uses the same electromagnetic filter to treat condensate during normal operation and condensate during start-up or stoppage in the same water passage, which has the following drawbacks.

In other words, the electromagnetic filter that normally processes condensate containing 5-10 ppb suspension method contains 500-1,000 ppb suspension method, although the flow rate has decreased to about %. If condensate is passed through during startup or shutdown, the removal rate of the suspension method of the electromagnetic filter will decrease, and the load on the subsequent condensate demineralization tower will increase. This results in an increase in the pressure loss of the desalination tower, which increases the frequency of regeneration, which is economically disadvantageous.

The present invention solves the above-mentioned drawbacks in the treatment of conventional electromagnetic filters, and provides a treatment method that can efficiently treat both condensate during normal operation of the boiler and at the time of startup or shutdown. When treating boiler condensate with an electromagnetic filter, multiple series of magnetic filler layers are installed, and when treating condensate during normal times, the condensate is passed through multiple series of magnetic filler layers in parallel, When the condensate water decreases, the flow rate decreases.

The present invention also relates to a method for treating an electromagnetic filter, which is characterized in that when treating condensate during startup or shutdown when the amount of suspended iron increases, the condensate is passed through a plurality of series of magnetic filler layers in series. It is something.

The present invention will be explained in detail below.

The present invention is based on the following knowledge regarding electromagnetic filters. In other words, the magnetic filler layer of electromagnetic filler is spiral-shaped and wool-shaped.

They are similar to steel balls and are packed several times more densely than normal sand filtration or pre-coated filtration, and are 2 inches in diameter. , the form of adsorption is the so-called volume r
Almost too much.

In such an electromagnetic filter that volumetrically removes the suspension method, when the suspension method of the water to be treated is as low as 5 to 10 ppb, if the predetermined layer height of the magnetic filler is maintained, the layer height can be increased even further. The removal rate of the suspension method does not change much even if the height is increased, but when the suspension method of the water to be treated is as high as 500 to 1,000 ppb, the removal rate of the suspension method changes depending on the height of the magnetic filler layer. The removal rate increases as the two-layer height increases.

On the other hand, although the pressure loss of an electromagnetic filter is affected to some extent by the amount of suspension in the water to be treated, the dominant factor is the flow rate of water passing through the electromagnetic filter.

In other words, the lower the flow rate, the greater the pressure loss.

The present invention takes advantage of such properties in an electromagnetic filter, and installs a plurality of magnetic filler layers in series to perform the following processing.

In other words, when treating normal condensate with a large flow rate and a small amount of suspended iron, water is passed through multiple series of magnetic filler layers in parallel to prevent pressure loss or increase, and also to reduce the flow rate. , and when treating condensate during startup or shutdown when the amount of suspended iron increases, the removal rate of the suspension method is increased by passing water through multiple series of magnetic filler layers in series.

In addition, when condensate water is passed through multiple series of magnetic filler layers in series as in the method of the present invention during start-up or stop, the pressure loss increases by about 3 to 4 times compared to when the condensate is connected in parallel. Although it increases, this value is small because the flow rate has decreased to about % as mentioned above.

The value does not become a problem.

In this way, the present invention installs a plurality of magnetic filler layers in series and changes the respective flow paths when treating condensate during normal operation and when treating condensate during startup or shutdown.

Both types of condensate can be efficiently treated.

In the present invention, there are two ways to install a plurality of lines of magnetic filler layers: a method of installing electromagnetic filters in a plurality of lines, and a method of forming a plurality of lines of magnetic filler layers in a packed tower. The former embodiment will be described in detail with reference to the drawings.

FIG. 1 is an explanatory diagram of the flow when two series of electromagnetic filters are installed.
2b, and electromagnetic filters A are connected to the inflow branch pipes 2a and 2b, respectively.

Connect the inlet side of B. Also, electromagnetic filter A.

Connect outflow branch pipes 3a and 3b to the outlet side of B, respectively,
The outflow branch pipes 3a and 3b are communicated with the outflow main pipe 4.

Further, a connecting pipe 5 is provided between the electromagnetic filters A and B to communicate the inflow main pipe 1 and the outflow main pipe 4.

A switching valve 6 is installed in the connecting pipe 5. A switching valve 7 is installed in the inflow main pipe 1 between the inflow branch pipe 2a and the connecting pipe 5, and a switching valve 7 is installed in the outflow main pipe 4 between the connecting pipe 5 and the outflow branch pipe 3b. Set 8.

There are various cleaning pipes around the electromagnetic filters A and B.
Valves are also included, but these piping and valves have been omitted. In addition, A22B and H2 are well-known condensate demineralization towers installed after the electromagnetic filters A and B, and are usually 3 to 3 times higher depending on the flow rate of condensate.
Install 4 towers.

When treating normal condensate that contains little suspended iron in the flow shown in Figure 1.

The switching valves 7 and 8 are opened, the switching valve 6 is closed, and the condensate is diverted from the inflow main pipe 1 to the inflow branch pipes 2a and 2b, respectively, the water is passed through the electromagnetic filters A and B in parallel, and the condensate is passed through the electromagnetic filters A and B in parallel. 3a.

The treated water flowing out from each of the pipes 3b is joined to the main pipe 4, and then passed to the subsequent condensate desalination towers 1 and 2.

By passing water in parallel in this way, it is possible to prevent pressure loss in the electromagnetic filter portion from increasing. In addition, the amount of suspended iron in condensate under normal conditions is small at 5 to 10 ppb.
As mentioned above, even if the condensate is passed through the electromagnetic filters A and B in series, the removal rate of suspended iron increases only slightly;
Pressure loss increases significantly. Therefore, it is not preferable to pass condensate water in series during normal operation.

Next, when treating condensate during startup or shutdown when suspended iron increases, switch valves 7 and 8 are closed, and switch valve 6 is opened.

The entire amount of condensate is passed through the electromagnetic filter A through the inflow main pipe U and the inflow branch pipe 2a, and the treated water is passed through the outflow branch pipe 3a and the connecting pipe 5. The electromagnetic filter B is supplied again via the inflow branch pipe 2b.
Condensate is passed through electromagnetic filters A and B in series, and the treated water is passed through subsequent condensate demineralization towers A to II. By passing water in series in this way,
The removal rate of suspended iron can be increased. Note that even if the water flow mode is switched to series, the flow rate is reduced to approximately the same level as described above, so the pressure loss in the electromagnetic filter portion does not increase to the extent that it becomes a problem.

FIG. 2 is an explanatory diagram of the flow when two magnetic filler layers are installed in one packed tower.

A water collection mechanism] 0 consisting of, for example, lateral piping with a large number of holes is provided in the approximately central part of the packed tower 9, and magnetic filler layers 8' and B' are placed above and below the water collection mechanism 10. Form.

Further, an inflow m pipe 1 is connected to the upper part of the packed tower 9, and a flow 111 header pipe 4 is connected to the lower part of the packed tower 9. Furthermore, a connecting pipe 5 is attached to communicate the inflow main pipe 1 and the outflow main pipe 4, one end of the water collection pipe 1 is still connected to the water collection mechanism JO, and the other end of the water collection pipe 11 is connected to the outflow main pipe 4. Communicate. In addition, the connecting pipe 5,
A switching valve 2 is installed on the outflow main pipe 41 and the water collection pipe 11, respectively.
, 13 and 14 are attached. Incidentally, Illu 2 is a condensate desalination tower installed at the latter stage, as in Fig. 1.

In the flow shown in Fig. 2, when treating condensate in normal conditions, switch valves 12 and 14 are pressed;
is closed, the condensate is passed through the inflow mother βJ and the magnetic filler layers A' and B' in parallel via the connecting pipe 5, and the treated water is collected by the water collection mechanism 10 and collected into the water collection pipe 11. The water is passed through to condensate demineralization towers A to II in the subsequent stage.

In addition, when treating condensate at startup or during normal operation, the switching valve 13 is opened and the switching valves 12 and 14 are closed to direct the condensate in series to the magnetic filler layers A' and B' via the inflow main pipe J. The treated water is passed through the outflow main pipe 4 to the subsequent condensate desalination towers A to II.

By forming a plurality of magnetic filler layers in the packed tower 9 as shown in Figure 2, one packed tower can be used for two lines of ordinary electromagnetic filters, which reduces the installation area of the device. can do.

When installing multiple series of electromagnetic filters.

Although the example in which two lines of electromagnetic filters are installed in Fig. 1 is explained, the present invention is not limited to this.
As shown in the figure, three series of electromagnetic filters A, B, and C are installed, and when treating condensate during normal conditions, three series of electromagnetic filters A and B are used to treat condensate as shown by the solid line flow path.

Water is passed through C in parallel, and when processing condensate during startup or shutdown, the condensate is passed through three series of electromagnetic filters A, as shown by the dotted line flow path.

Water can also be passed through B and C in series.

As shown in Figure 4, the electromagnetic filters are A, B,
Four series C and D are installed, and when treating condensate in normal conditions, condensate is passed through four series of electromagnetic filters A, B, C, and D in parallel, as shown by the solid line flow path. When treating condensate during startup or shutdown, as shown by the dotted line flow path, two series of electromagnetic filters A and B and electromagnetic filters C2 and D are used as one set, and each of these two series of electromagnetic filters is Condensate water can also be passed in series.

Next, the electromagnetic filter used in the present invention will be explained.

In the electromagnetic filter used in the present invention, a magnetic filler such as a spiral, wool, or steel ball, or a combination of these magnetic fillers is packed in layers in a packed tower.

An electromagnetic coil is installed around the outer periphery of the packed tower. When removing suspended iron in condensate, an electric current is passed through the electromagnetic coil to magnetize the magnetic packing material layer, and the condensate is drawn from the top or bottom of the packed tower. When the suspended iron flows in and is adsorbed to the magnetic filler layer by magnetic force, and the suspended iron that is still adsorbed to the magnetic filler layer is to be washed, the current of the electromagnetic coil is turned off.

An ordinary electromagnetic filter can be used that allows washing water or air to flow into the packed tower to separate suspended iron adsorbed to the magnetic packing layer. In some cases, an electromagnetic filter filled with a magnetic filler made of permanent magnets may also be used.

As explained above, by the treatment method of the present invention, in the case of condensate under normal conditions, it is possible to measure the reduction in pressure loss without significantly reducing the removal rate of suspended iron. In the case of condensate water, the removal rate of suspended iron can be increased without significantly increasing the pressure loss, and both condensate waters can be effectively treated by electric filters.

Especially when installing a condensate desalination tower in the latter stage.

By carrying out the present invention, it is possible to reduce the load on the condensate demineralization tower due to suspended iron.

The present invention will be explained in detail below.

Example Assuming condensate water during normal operation, startup, or shutdown of a boiler in a thermal power plant 1. Electromagnetic treatment of synthetic water 2. The following water flow test was conducted using Ilter 2 series.

(1) Test conditions (] ) -1, Electromagnetic filter packed tower used; diameter 5
4 mm, height 600mm Filling material: Composite filling of spiral band and stainless steel cool, filling bed height 400 mm (1)-2, Test method When electromagnetic filters are used in parallel.

When used in series, synthetic water assuming normal condensation and synthetic water assuming condensation at startup or shutdown are passed through each, and the suspension method and pressure loss of the treated water at that time are investigated. It was measured. In addition, when passing synthetic water assuming condensation during startup or shutdown, the 2-pass water LV was lowered to % of the normal time.

(2) Test results When two towers are connected in parallel, the water flow LV indicates the LV of one tower.

(The same applies to Table 2.) 2nd Precedent Condensate treatment results assuming startup or shutdown.) 2. As seen in Tables K and 2, under normal conditions, water flows through the 2 column rows. Comparing water flow through two tower rows, there is not much difference in the iron removal rate, but in the case of water flow through two tower rows, the pressure loss increases by about 5 times, and it becomes worse when starting up or stopping. case.

Comparing water flow through two tower rows and water flow through two tower rows.

The iron removal rate is better when water is passed through two columns.

And the pressure loss is about 3 by connecting two columns in series.
It increases by ~4 times, but even though it increases, it is around 0.5 /, /r:n1, so it is not a problem. Therefore, for condensate water under normal conditions, two-column column water passage is better, and for condensate water at startup or stoppage, two-column column water passage is better.

[Brief explanation of drawings]

Both Figures 1 to 4 show embodiments of the present invention. Figure 1 is an explanatory diagram of the flow when two lines of electromagnetic filters are installed, and Figure 2 is an explanatory diagram of the flow when two lines of electromagnetic filters are installed. FIG. 3 is an explanatory diagram of the flow in the case where three series of electromagnetic filters are installed. FIG. 4 is an explanatory diagram of the flow when four series of electromagnetic filters are installed. 1... Inflow main pipe 2... Inflow branch pipe 3...
Outflow branch pipe 4/Outflow cut pipe 5...Connection pipe
6. '2. Meter/switching valve 9... Packed tower
lO...Water collection mechanism Co-1...Water collection pipe
12.13.14-°・Switching valve A, B, C, D
...Electromagnetic filter A/, B/...Magnetic filler layer Figure 1 Figure 2 J2 Jj 4 Procedural amendment (voluntary) October 14, 1981 Kazuo Wakasugi, Commissioner of the Patent Office/, Incident Indication of Patent Application No. 122914 filed in 1982 (S1) Name of the invention Processing method for electromagnetic filters 3. Relationship with the person making the amendment Applicant ≠ Agent 〒113 No. 4] Page 6 of the table is as follows: correct. ]-Table Condensate treatment results assuming normal times 17I)
The water flows r and v in the case of a two-tower row indicate the LV of one tower. (The same applies to Table 2) 2. Table 2 on page 17 is corrected as follows. Table 2: Results of condensate treatment assuming startup or shutdown.

Claims (2)

[Claims] (1) When treating boiler condensate at a power plant with an electromagnetic filter, multiple lines of magnetic filler layers are installed to treat condensate during normal times. The condensate is passed through multiple series of magnetic filler layers in parallel, and the flow rate is lower than that of normal condensate. A method for treating an electromagnetic filter, characterized in that when treating condensate during startup or shutdown when the amount of suspended iron increases, the condensate is passed through a plurality of series of magnetic filler layers in series. (2) A packed tower with a water collection mechanism installed in the center of the tank and magnetic filler layers arranged above and below the water collection mechanism is used, and when treating condensate in normal conditions, the upper part of the packed tower is Then, condensate flows in from the lower part, and the treated water flows out from the water collecting mechanism and flows in parallel to the magnetic filler layer. When treating condensate during startup or shutdown,
The electromagnetic device according to claim 1, wherein condensate flows in from the upper or lower part of the packed tower, and the treated water flows out from the lower or upper part of the electromagnetic filter and flows in series to the magnetic filler layer. How to process filters