JPH0659370B2 - Reproducing method of filter media in electromagnetic filter in magnetic separation device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial field of application> The present invention relates to a method for reproducing filter media in an electromagnetic filter in a magnetic separation device.

Separation of magnetic components in the untreated liquid by treating these untreated liquids such as various types of waste liquids such as coolant waste liquid for cold rolling, and further domestic wastewater, which are discharged during manufacturing or processing of steel products. A magnetic separator is used for recovery.
This type of magnetic separation device is a device whose core is an electromagnetic filter that captures a magnetic component by a filter medium in a magnetic field formed by an exciting coil, but the untreated liquid as described above is continuously supplied to the electromagnetic filter. After passing through and processing
Since the magnetic components that are sequentially captured accumulate on the filter medium and oil and the like also adhere to the filter medium, the filter medium must be regenerated, for example, at regular intervals in order to make the electromagnetic filter effectively function as expected. .

The present invention relates to an improvement in the method for reproducing the above filter media.

<Prior Art and Its Problems> Conventionally, as a method of reproducing a filter medium in an electromagnetic filter in a magnetic separation device, compressed air is first ejected from the outlet into the electromagnetic filter to remove the stagnant liquid in the electromagnetic filter. After removing from the inlet, then introducing excess steam into the electromagnetic filter from the outlet to strongly adhere to the filter media while weakening traps or deposits, while discharging excess steam from the inlet, Finally, the backwashing liquid heated to a predetermined temperature from the outlet of the electromagnetic filter is jetted together with the compressed air to discharge the weakened trapped substance or adhered substance from the inlet. (JP-A-58-216713).

However, according to the conventional method as described above, the excess steam introduced into the electromagnetic filter at the time of regeneration is discharged to the outside of the system in a high temperature state as it is, which is unfavorable for the environment and is particularly dangerous to the worker. There is also a problem that the thermal energy of the steam is wasted.

<Problems to be Solved by the Invention and Means for Solving the Problems> The present invention solves the problems of the conventional methods as described above. In particular, an operator does not have an environmental problem when playing a filter medium. The present invention provides a method of regenerating a filter medium in an electromagnetic filter in a magnetic separation device, which can be safely regenerated, and can effectively utilize the thermal energy of steam used for the regeneration.

Therefore, the present invention is a method of regenerating a filter medium in an electromagnetic filter in a magnetic separation device used for separating and recovering a magnetic component in an untreated liquid, which includes the following first to third steps. The present invention relates to a reproducing method characterized by the above.

First step: a step of ejecting compressed air into the electromagnetic filter from its outlet to remove retained liquid in the electromagnetic filter from its inlet. Second step: introducing electromagnetic vapor into the electromagnetic filter from its outlet to introduce the electromagnetic filter. While softening the trapped substances or deposits of the filter media inside, the excess steam is returned from its inlet to a pressure tank that has been preheated with another steam or is being preheated with a backwash liquid. And a step of using the backwash solution as an auxiliary to heat the backwash solution to a predetermined temperature. Third step: A trapped material which has been weakened by injecting the backwash solution heated to a predetermined temperature from its outlet into the electromagnetic filter together with pressurized air. Through the step of discharging the deposits from the inlet, the essential point in the present invention is the steam introduced from the inlet into the electromagnetic filter in order to weaken the trapped substances or deposits of the filter media. The excess amount of is returned to the pressure tank from its outlet, and in the place where it is used as an auxiliary to heat the backwash liquid that has been or is being preheated in the pressure tank to the predetermined temperature by the returned steam. is there.

In the present invention, the conventional method of discharging the surplus of the steam introduced into the electromagnetic filter to the outside of the system as it is in a high temperature state is used for heating the backwash liquid by returning the surplus to the pressure tank. There is no environmental problem, it is completely safe especially for workers, and the surplus heat energy can be effectively used.

Hereinafter, the configuration of the present invention will be described in more detail with reference to the drawings.

<Example> FIG. 1 is a system diagram showing an embodiment of the present invention. An exciting coil 11 is provided outside, and an untreated liquid inlet 31 and a treated liquid outlet 32 are provided in an electromagnetic filter 21 containing a filter medium 12. At the inlet 31, a pipe 41 for the untreated liquid and a pipe 42 for discharging the used backwash liquid
However, a pipe 43 for processing liquid, a pipe 44 for steam, a pipe 45 for backwash liquid from the pressure tank 61, and a pipe 46 for compressed air from the receiving tank 62 are appropriately provided at the outlet 32, respectively. The pipes 41 to 46 are connected while being partially shared, and valves 71 to 76 are interposed in the respective pipes 41 to 46.
Further, the pressurized tank 61 is provided so that the untreated liquid pipe 41 and the treated liquid pipe 43 can be short-circuited via the valve 77.
To the receiving tank 62 so that the backwashing liquid can be fed into the receiving tank 62 via the valve 78, and the backwashing liquid fed into the pressurized tank 61 via the valve 79. To heat the steam into the pressure tank 61 while receiving the steam in the pressure tank 61.
So that compressed air can be introduced through the valve 80 from
Each is connected by piping.

Then, the inlet 3 for the untreated liquid in the electromagnetic filter 21
1 and a backwashing liquid pressurized tank 61 are connected via a valve 81 by a pipe 47 for returning steam, and at the time of regenerating the filter medium 12 as described later, via a valve 74 and a pipe 44 for steam. From the outlet 32 to the electromagnetic filter 2
The steam introduced into the No. 1 is returned to the pressure tank 61 for the backwash liquid, and the backwash liquid previously fed into the pressure tank 61 is used as an auxiliary for heating to a predetermined temperature. .

The exciting coil 11 is energized, and the valve 71 / pipe 41 → electromagnetic filter 21 (inlet 31 → filter media 12 →
When the untreated liquid is magnetically separated through the path from the outlet 32) to the pipe 43 and the valve 73, the magnetic components that are sequentially captured are accumulated in the filter medium 12, and oil and the like are also attached. Play (eg, every hour).

Reproduction is performed in the following procedure. First, the receiving tank 62 → the pipe 46 / the valve 76 → the electromagnetic filter 21 (the outlet 32 →
The filter medium 12 → the inlet 31, and the same order hereinafter) → The flow of the pipe 41 and the valve 77 removes the stagnant liquid in the electromagnetic filter 21 by jetting the compressed air. Next, by introducing steam into the electromagnetic filter 21 along the route of the valve 74 / pipe 44 → electromagnetic filter 21 → valve 81 / pipe 47 → pressurization tank 61, oil and the like can be firmly fixed to the filter medium 12. Excessive steam is pressurized in the pressure tank 6 while weakening certain trapped substances or attached substances.
It is returned to No. 1 and is used as an auxiliary for heating the backwash liquid which has been previously sent into the pressurized tank 61 by the steam through the valve 78 to a predetermined temperature. The backwash liquid that has been sent into the pressure tank 61 is supplied to the pressure tank 6 via the valve 79.
Preheated by the steam introduced into the valve 1, but the valve 8
1. The steam returned to the pressure tank 61 through the above-mentioned path including the pipe 47 compensates for the shortage of the preheating and heats the backwash liquid to a predetermined temperature. Finally, at least at this stage, the energization of the exciting coil 11 is stopped, and the pressurized tank 61 → the pipe 45 / the valve while introducing the compressed air into the pressurized tank 61 through the route of the receiving tank 62 → the valve 80 → the pressurized tank 61. The filter medium 12 is regenerated by injecting the backwashing liquid heated to a predetermined temperature into the electromagnetic filter 21 through the path of 75 → electromagnetic filter 21 → valve 72 / pipe 42. In the following, the magnetic separation device for the untreated liquid and the reproduction of the filter medium 12 are similarly repeated.

In the conventional method, the surplus vapor introduced into the electromagnetic filter at the time of reproducing the filter media is discharged to the outside of the system in a high temperature state as it is (referring to the number in FIG. 1, the valve 74 / the pipe 44 → the electromagnetic filter 21 → Valve 72
The route of the pipe 42) has the above-mentioned problems. In the present invention, such a conventional problem can be solved by the method of reproducing the filter medium described above.

According to the procedure described above for one embodiment shown in FIG. 1, the cold rolling coolant used in the manufacturing process of steel products was magnetically separated, and the filter media was regenerated under the following conditions. There are no environmental problems associated with the introduction of steam into the electromagnetic filter, and it is absolutely safe for workers, and the backwash liquid (water) in the pressurized tank is 8
Since it is only necessary to preheat to about 4 ° C (the backwash liquid reaches the set temperature of 90 ° C due to the returned steam), the heat energy could be effectively utilized by that much.

Conditions: Electromagnetic filter inner diameter 1000 mm, backwash liquid amount 3.5
m ³ / times, backwash liquid initial temperature 20 ° C, backwash liquid set temperature 90
℃, the amount of steam introduced into the electromagnetic filter 78.5kg / time,
Same steam enthalpy 650 Kcal / kg, backwash frequency 1 time /
Time.

<Advantages of the Invention> As is apparent, the present invention described above does not cause any environmental problem when reproducing the filter media in the electromagnetic filter in the magnetic separation device, and is particularly safe for workers. There is also an effect that the thermal energy of steam can be effectively used.

[Brief description of drawings]

 FIG. 1 is a system diagram showing an embodiment of the present invention. 11 …… Excitation coil, 12 …… Filter media, 21 …… Electromagnetic filter, 31 …… Inlet, 32 …… Outlet, 41 …… 47 …… Piping, 61 …… Pressure tank, 62 …… Reception tank, 71 ～ 79, 80, 81 ... Valve

Front page continuation (72) Inventor Shuichi Ichikawa 2-229, Mineoka-cho, Hodogaya-ku, Yokohama-shi, Kanagawa (72) Inventor Junichi Yano 1-326, Umegaoka, Chita-shi, Aichi (56) References 59-115717 (JP, A) JP-A-57-50583 (JP, A)

Claims (1)

[Claims] 1. A method for regenerating a filter medium in an electromagnetic filter in a magnetic separation device used for separating and recovering a magnetic component in an untreated liquid, which comprises the following first to third steps. Playback method characterized by. First step: a step of ejecting compressed air into the electromagnetic filter from its outlet to remove retained liquid in the electromagnetic filter from its inlet. Second step: introducing electromagnetic vapor into the electromagnetic filter from its outlet to introduce the electromagnetic filter. While softening the trapped substances or deposits of the filter media inside, the excess steam is returned from its inlet to a pressure tank that has been preheated with another steam or is being preheated with a backwash liquid. And a step of using the backwash solution as an auxiliary to heat the backwash solution to a predetermined temperature. Third step: A trapped material which has been weakened by injecting the backwash solution heated to a predetermined temperature from its outlet into the electromagnetic filter together with pressurized air. Or the process of discharging adhered substances from the inlet